diff --git a/src/$ColorBox.js b/src/$ColorBox.js
index 75d16b4..0607c06 100644
--- a/src/$ColorBox.js
+++ b/src/$ColorBox.js
@@ -5,7 +5,7 @@ function $Swatch(color){
 	var swatch_canvas = new Canvas();
 	$(swatch_canvas).css({pointerEvents: "none"}).appendTo($b);
 	
-	$b.update = function(_color){
+	$b.update = _color => {
 		color = _color;
 		if(color instanceof CanvasPattern){
 			$b.addClass("pattern");
@@ -13,7 +13,7 @@ function $Swatch(color){
 			$b.removeClass("pattern");
 		}
 		
-		requestAnimationFrame(function(){
+		requestAnimationFrame(() => {
 			swatch_canvas.width = $b.innerWidth();
 			swatch_canvas.height = $b.innerHeight();
 			// I don't think disable_image_smoothing() is needed here
@@ -24,7 +24,7 @@ function $Swatch(color){
 			}
 		});
 	};
-	$G.on("theme-load", function(){
+	$G.on("theme-load", () => {
 		$b.update(color);
 	});
 	$b.update(color);
@@ -58,13 +58,13 @@ function $ColorBox(){
 		bottom: 3,
 	});
 	
-	$G.on("option-changed", function(){
+	$G.on("option-changed", () => {
 		$foreground_color.update(colors.foreground);
 		$background_color.update(colors.background);
 		$current_colors.update(colors.ternary);
 	});
 	
-	$current_colors.on("pointerdown", function(){
+	$current_colors.on("pointerdown", () => {
 		var new_bg = colors.foreground;
 		colors.foreground = colors.background;
 		colors.background = new_bg;
@@ -77,9 +77,9 @@ function $ColorBox(){
 	// TODO: base this on the element sizes
 	var width_per_button = 16;
 	
-	var build_palette = function(){
+	var build_palette = () => {
 		$palette.empty();
-		$.each(palette, function(i, color){
+		$.each(palette, (i, color) => {
 			var $b = $Swatch(color).addClass("color-button");
 			$b.appendTo($palette);
 			
@@ -90,7 +90,7 @@ function $ColorBox(){
 			
 			var $i = $(E("input")).attr({type: "color"});
 			$i.appendTo($b);
-			$i.on("change", function(){
+			$i.on("change", () => {
 				color = $i.val();
 				$b.update(color);
 				set_color(color);
@@ -102,7 +102,7 @@ function $ColorBox(){
 			$i.val(rgb2hex(color));
 			
 			var button, ctrl;
-			$b.on("pointerdown", function(e){
+			$b.on("pointerdown", e => {
 				// TODO: how should the ternary color, and selection cropping, work on macOS?
 				ctrl = e.ctrlKey;
 				button = e.button;
@@ -119,11 +119,11 @@ function $ColorBox(){
 				}
 				
 				$i.prop("enabled", true);
-				setTimeout(function(){
+				setTimeout(() => {
 					$i.prop("enabled", false);
 				}, 400);
 			});
-			$i.on("click", function(e, synthetic){
+			$i.on("click", (e, synthetic) => {
 				if(!synthetic){
 					e.preventDefault();
 				}
@@ -156,9 +156,9 @@ function $ColorBox(){
 	
 	var $c = $Component("Colors", "wide", $cb);
 	
-	$c.edit_last_color = function(){
+	$c.edit_last_color = () => {
 		// Edit the last color cell that's been selected as the foreground color.
-		create_and_trigger_input({type: "color"}, function(input){
+		create_and_trigger_input({type: "color"}, input => {
 			// console.log(input, input.value);
 			$last_fg_color_button.trigger({type: "pointerdown", ctrlKey: false, button: 0});
 			$last_fg_color_button.find("input").val(input.value).triggerHandler("change");
diff --git a/src/$Component.js b/src/$Component.js
index fa196bd..042200d 100644
--- a/src/$Component.js
+++ b/src/$Component.js
@@ -36,7 +36,7 @@ function $Component(name, orientation, $el){
 		pos_axis = "left";
 	}
 	
-	var dock_to = function($dock_to){
+	var dock_to = $dock_to => {
 		$w.hide();
 		
 		$dock_to.append($c);
@@ -60,13 +60,13 @@ function $Component(name, orientation, $el){
 	var $last_docked_to;
 	var $dock_to;
 	var $ghost;
-	$c.on("pointerdown", function(e){
+	$c.on("pointerdown", e => {
 		// Only start a drag via a left click directly on the component element
 		if(e.button !== 0){ return; }
 		if(!$c.is(e.target)){ return; }
 		
 		$G.on("pointermove", drag_onpointermove);
-		$G.one("pointerup", function(e){
+		$G.one("pointerup", e => {
 			$G.off("pointermove", drag_onpointermove);
 			drag_onpointerup(e);
 		});
@@ -94,7 +94,7 @@ function $Component(name, orientation, $el){
 		// Prevent text selection anywhere within the component
 		e.preventDefault();
 	});
-	var drag_onpointermove = function(e){
+	var drag_onpointermove = e => {
 		
 		$ghost.css({
 			left: e.clientX + ox,
@@ -135,7 +135,7 @@ function $Component(name, orientation, $el){
 		e.preventDefault();
 	};
 	
-	var drag_onpointerup = function(e){
+	var drag_onpointerup = e => {
 		
 		$w.hide();
 		
@@ -175,23 +175,23 @@ function $Component(name, orientation, $el){
 		$G.trigger("resize");
 	};
 	
-	$c.dock = function(){
+	$c.dock = () => {
 		pos = last_docked_to_pos;
 		dock_to($last_docked_to);
 	};
 	
-	$c.show = function(){
+	$c.show = () => {
 		$($c[0]).show(); // avoid recursion
 		if($.contains($w[0], $c[0])){
 			$w.show();
 		}
 		return $c;
 	};
-	$c.hide = function(){
+	$c.hide = () => {
 		$c.add($w).hide();
 		return $c;
 	};
-	$c.toggle = function(){
+	$c.toggle = () => {
 		if($c.is(":visible")){
 			$c.hide();
 		}else{
@@ -200,7 +200,7 @@ function $Component(name, orientation, $el){
 		return $c;
 	};
 	
-	$w.on("close", function(e){
+	$w.on("close", e => {
 		e.preventDefault();
 		$w.hide();
 	});
diff --git a/src/$FontBox.js b/src/$FontBox.js
index 2703e55..bf7c88d 100644
--- a/src/$FontBox.js
+++ b/src/$FontBox.js
@@ -22,13 +22,13 @@ function $FontBox(){
 	$button_group.append($bold, $italic, $underline, $vertical);
 	$fb.append($family, $size, $button_group);
 	
-	var update_font = function(){
+	var update_font = () => {
 		text_tool_font.size = Number($size.val());
 		text_tool_font.family = $family.val();
 		$G.trigger("option-changed");
 	};
 	
-	FontDetective.each(function(font){
+	FontDetective.each(font => {
 		var $option = $(E("option"));
 		$option.val(font).text(font.name);
 		$family.append($option);
@@ -65,7 +65,7 @@ function $FontBox(){
 			backgroundImage: "url(images/text-tools.png)",
 			backgroundPosition: xi*-16 + "px 0px"
 		});
-		$button.on("click", function(){
+		$button.on("click", () => {
 			$button.toggleClass("selected");
 			text_tool_font[thing] = $button.hasClass("selected");
 			update_font();
diff --git a/src/$Handles.js b/src/$Handles.js
index 4f1e5f4..34ff720 100644
--- a/src/$Handles.js
+++ b/src/$Handles.js
@@ -1,11 +1,11 @@
 
 function $Handles($container, element, options){
 	var outset = options.outset || 0;
-	var get_offset_left = options.get_offset_left || function(){ return 0; };
-	var get_offset_top = options.get_offset_top || function(){ return 0; };
+	var get_offset_left = options.get_offset_left || (() => { return 0; });
+	var get_offset_top = options.get_offset_top || (() => { return 0; });
 	var size_only = options.size_only || false;
 	var el = element;
-	$container.on("new-element", function(e, element){
+	$container.on("new-element", (e, element) => {
 		el = element;
 	});
 	
@@ -19,7 +19,7 @@ function $Handles($container, element, options){
 		["bottom", "middle"], // ↓
 		["bottom", "right"], // ↘
 		["middle", "right"], // →
-	], function(pos){
+	], pos => {
 		var y_axis = pos[0];
 		var x_axis = pos[1];
 		
@@ -57,7 +57,7 @@ function $Handles($container, element, options){
 			cursor = Cursor([cursor_fname, [16, 16], cursor]);
 			$h.css({cursor: cursor});
 			
-			var drag = function(e){
+			var drag = e => {
 				$resize_ghost.appendTo($container);
 				dragged = true;
 				
@@ -91,13 +91,13 @@ function $Handles($container, element, options){
 					height: magnification * height,
 				});
 			};
-			$h.on("pointerdown", function(e){
+			$h.on("pointerdown", e => {
 				dragged = false;
 				if(e.button === 0){
 					$G.on("pointermove", drag);
 					$("body").css({cursor: cursor}).addClass("cursor-bully");
 				}
-				$G.one("pointerup", function(e){
+				$G.one("pointerup", e => {
 					$G.off("pointermove", drag);
 					$("body").css({cursor: ""}).removeClass("cursor-bully");
 					
@@ -108,12 +108,12 @@ function $Handles($container, element, options){
 					$container.trigger("update");
 				});
 			});
-			$h.on("mousedown selectstart", function(e){
+			$h.on("mousedown selectstart", e => {
 				e.preventDefault();
 			});
 		}
 		
-		var update_handle = function(){
+		var update_handle = () => {
 			var rect = el.getBoundingClientRect();
 			var hs = $h.width();
 			if(x_axis === "middle"){
diff --git a/src/$MenuBar.js b/src/$MenuBar.js
index 6068562..14db6c9 100644
--- a/src/$MenuBar.js
+++ b/src/$MenuBar.js
@@ -13,22 +13,22 @@ function $MenuBar(menus){
 	$menus.attr("touch-action", "none");
 	var selecting_menus = false;
 	
-	var _html = function(menus_key){
-		return menus_key.replace(/&(.)/, function(m){
+	var _html = menus_key => {
+		return menus_key.replace(/&(.)/, m => {
 			return "<span class='menu-hotkey'>" + m[1] + "</span>";
 		});
 	};
-	var _hotkey = function(menus_key){
+	var _hotkey = menus_key => {
 		return menus_key[menus_key.indexOf("&")+1].toUpperCase();
 	};
 	
-	var close_menus = function(){
+	var close_menus = () => {
 		$menus.find(".menu-button").trigger("release");
 		// Close any rogue floating submenus
 		$(".menu-popup").hide();
 	};
 	
-	var is_disabled = function(item){
+	var is_disabled = item => {
 		if(typeof item.enabled === "function"){
 			return !item.enabled();
 		}else if(typeof item.enabled === "boolean"){
@@ -43,7 +43,7 @@ function $MenuBar(menus){
 		var $menu_popup = $(E("div")).addClass("menu-popup");
 		var $menu_popup_table = $(E("table")).addClass("menu-popup-table").appendTo($menu_popup);
 		
-		$.map(menu_items, function(item){
+		$.map(menu_items, item => {
 			var $row = $(E("tr")).addClass("menu-row").appendTo($menu_popup_table)
 			if(item === $MenuBar.DIVIDER){
 				var $td = $(E("td")).attr({colspan: 4}).appendTo($row);
@@ -62,13 +62,13 @@ function $MenuBar(menus){
 				$label.html(_html(item.item));
 				$shortcut.text(item.shortcut);
 				
-				$menu_popup.on("update", function(){
+				$menu_popup.on("update", () => {
 					$item.attr("disabled", is_disabled(item));
 					if(item.checkbox && item.checkbox.check){
 						$checkbox_area.text(item.checkbox.check() ? "✓" : "");
 					}
 				});
-				$item.on("pointerover", function(){
+				$item.on("pointerover", () => {
 					$menu_popup.triggerHandler("update");
 					$item[0].focus();
 				});
@@ -83,7 +83,7 @@ function $MenuBar(menus){
 					var $submenu_popup = $MenuPopup(item.submenu).appendTo("body");
 					$submenu_popup.hide();
 					
-					var open_submenu = function(){
+					var open_submenu = () => {
 						$submenu_popup.show();
 						$submenu_popup.triggerHandler("update");
 						var rect = $submenu_area[0].getBoundingClientRect();
@@ -94,27 +94,27 @@ function $MenuBar(menus){
 						});
 					};
 					var open_tid, close_tid;
-					$item.add($submenu_popup).on("pointerover", function(e){
+					$item.add($submenu_popup).on("pointerover", e => {
 						if(open_tid){clearTimeout(open_tid);}
 						if(close_tid){clearTimeout(close_tid);}
 					});
-					$item.on("pointerover", function(e){
+					$item.on("pointerover", e => {
 						if(open_tid){clearTimeout(open_tid);}
 						if(close_tid){clearTimeout(close_tid);}
 						open_tid = setTimeout(open_submenu, 200);
 					});
-					$item.add($submenu_popup).on("pointerout", function(){
+					$item.add($submenu_popup).on("pointerout", () => {
 						$menu_popup.closest(".menu-container").find(".menu-button")[0].focus();
 						if(open_tid){clearTimeout(open_tid);}
 						if(close_tid){clearTimeout(close_tid);}
-						close_tid = setTimeout(function(){
+						close_tid = setTimeout(() => {
 							$submenu_popup.hide();
 						}, 200);
 					});
 					$item.on("click pointerdown", open_submenu);
 				}
 				
-				var item_action = function(){
+				var item_action = () => {
 					if(item.checkbox){
 						if(item.checkbox.toggle){
 							item.checkbox.toggle();
@@ -125,20 +125,20 @@ function $MenuBar(menus){
 						item.action();
 					}
 				};
-				$item.on("pointerup", function(e){
+				$item.on("pointerup", e => {
 					if(e.pointerType === "mouse" && e.button !== 0){
 						return;
 					}
 					item_action();
 				});
-				$item.on("pointerover", function(){
+				$item.on("pointerover", () => {
 					if(item.submenu){
 						$menus.triggerHandler("info", "");
 					}else{
 						$menus.triggerHandler("info", item.description || "");
 					}
 				});
-				$item.on("pointerout", function(){
+				$item.on("pointerout", () => {
 					if($item.is(":visible")){
 						$menus.triggerHandler("info", "");
 						// may not exist for submenu popups
@@ -149,7 +149,7 @@ function $MenuBar(menus){
 					}
 				});
 				
-				$item.on("keydown", function(e){
+				$item.on("keydown", e => {
 					if(e.ctrlKey || e.shiftKey || e.altKey || e.metaKey){
 						return;
 					}
@@ -159,7 +159,7 @@ function $MenuBar(menus){
 					}
 				});
 				
-				$menu_popup.on("keydown", function(e){
+				$menu_popup.on("keydown", e => {
 					if(e.ctrlKey || e.shiftKey || e.altKey || e.metaKey){
 						return;
 					}
@@ -175,7 +175,7 @@ function $MenuBar(menus){
 	}
 	
 	var this_click_opened_the_menu = false;
-	$.each(menus, function(menus_key, menu_items){
+	$.each(menus, (menus_key, menu_items) => {
 		var $menu_container = $(E("div")).addClass("menu-container").appendTo($menus);
 		var $menu_button = $(E("div")).addClass("menu-button").appendTo($menu_container);
 		var $menu_popup = $MenuPopup(menu_items).appendTo($menu_container);
@@ -199,7 +199,7 @@ function $MenuBar(menus){
 		$menu_popup.hide();
 		$menu_button.html(_html(menus_key));
 		$menu_button.attr("tabIndex", -1)
-		$menu_container.on("keydown", function(e){
+		$menu_container.on("keydown", e => {
 			var $focused_item = $menu_popup.find(".menu-item:focus");
 			switch(e.keyCode){
 				case 37: // Left
@@ -240,7 +240,7 @@ function $MenuBar(menus){
 					break;
 			}
 		});
-		$G.on("keydown", function(e){
+		$G.on("keydown", e => {
 			if(e.ctrlKey || e.metaKey){ // Ctrl or Command held
 				if(e.keyCode !== 17 && e.keyCode !== 91 && e.keyCode !== 93 && e.keyCode !== 224){ // anything but Ctrl or Command pressed
 					close_menus();
@@ -254,7 +254,7 @@ function $MenuBar(menus){
 				}
 			}
 		});
-		$menu_button.on("pointerdown pointerover", function(e){
+		$menu_button.on("pointerdown pointerover", e => {
 			if(e.type === "pointerover" && !selecting_menus){
 				return;
 			}
@@ -275,7 +275,7 @@ function $MenuBar(menus){
 			
 			$menus.triggerHandler("info", "");
 		});
-		$menu_button.on("pointerup", function(e){
+		$menu_button.on("pointerup", e => {
 			if(this_click_opened_the_menu){
 				this_click_opened_the_menu = false;
 				return;
@@ -284,7 +284,7 @@ function $MenuBar(menus){
 				close_menus();
 			}
 		});
-		$menu_button.on("release", function(e){
+		$menu_button.on("release", e => {
 			selecting_menus = false;
 			
 			$menu_button.removeClass("active");
@@ -293,16 +293,16 @@ function $MenuBar(menus){
 			$menus.triggerHandler("default-info");
 		});
 	});
-	$G.on("keypress", function(e){
+	$G.on("keypress", e => {
 		if(e.keyCode === 27){ // Esc
 			close_menus();
 		}
 	});
-	$G.on("blur", function(e){
+	$G.on("blur", e => {
 		// console.log("blur", e.target, document.activeElement);
 		close_menus();
 	});
-	$G.on("pointerdown pointerup", function(e){
+	$G.on("pointerdown pointerup", e => {
 		if($(e.target).closest(".menus, .menu-popup").length === 0){
 			// console.log(e.type, "occurred outside of menus (on ", e.target, ") so...");
 			close_menus();
diff --git a/src/$ToolBox.js b/src/$ToolBox.js
index fcdb2b6..2859cec 100644
--- a/src/$ToolBox.js
+++ b/src/$ToolBox.js
@@ -5,12 +5,12 @@ function $ToolBox(tools, is_extras){
 	var $tool_options = $(E("div")).addClass("tool-options");
 	
 	var showing_tooltips = false;
-	$tools.on("pointerleave", function(){
+	$tools.on("pointerleave", () => {
 		showing_tooltips = false;
 		$status_text.default();
 	});
 	
-	var $buttons = $($.map(tools, function(tool, i){
+	var $buttons = $($.map(tools, (tool, i) => {
 		var $b = $(E("div")).addClass("tool");
 		$b.appendTo($tools);
 		tool.$button = $b;
@@ -36,7 +36,7 @@ function $ToolBox(tools, is_extras){
 		update_css();
 		$G.on("theme-load", update_css);
 		
-		$b.on("click", function(e){
+		$b.on("click", e => {
 			if (e.shiftKey || e.ctrlKey) {
 				select_tool(tool, true);
 				return;
@@ -48,8 +48,8 @@ function $ToolBox(tools, is_extras){
 			}
 		});
 		
-		$b.on("pointerenter", function(){
-			var show_tooltip = function(){
+		$b.on("pointerenter", () => {
+			var show_tooltip = () => {
 				showing_tooltips = true;
 				$status_text.text(tool.description);
 			};
@@ -57,7 +57,7 @@ function $ToolBox(tools, is_extras){
 				show_tooltip();
 			}else{
 				var tid = setTimeout(show_tooltip, 300);
-				$b.on("pointerleave", function(){
+				$b.on("pointerleave", () => {
 					clearTimeout(tid);
 				});
 			}
@@ -67,7 +67,7 @@ function $ToolBox(tools, is_extras){
 	}));
 	
 	var $c = $Component(is_extras ? "Extra Tools" : "Tools", "tall", $tools.add($tool_options));
-	$c.update_selected_tool = function(){
+	$c.update_selected_tool = () => {
 		$buttons.removeClass("selected");
 		selected_tools.forEach((selected_tool)=> {
 			selected_tool.$button.addClass("selected");
diff --git a/src/$Window.js b/src/$Window.js
index f394e42..a667060 100644
--- a/src/$Window.js
+++ b/src/$Window.js
@@ -14,10 +14,10 @@ function $Window($component){
 	
 	$w.attr("touch-action", "none");
 	
-	$w.$x.on("click", function(){
+	$w.$x.on("click", () => {
 		$w.close();
 	});
-	$w.$x.on("mousedown selectstart", function(e){
+	$w.$x.on("mousedown selectstart", e => {
 		e.preventDefault();
 	});
 	
@@ -29,13 +29,13 @@ function $Window($component){
 		position: "absolute",
 		zIndex: $Window.Z_INDEX++
 	});
-	$w.on("pointerdown", function(){
+	$w.on("pointerdown", () => {
 		$w.css({
 			zIndex: $Window.Z_INDEX++
 		});
 	});
 	
-	$w.on("keydown", function(e){
+	$w.on("keydown", e => {
 		if(e.ctrlKey || e.altKey || e.shiftKey || e.metaKey){
 			return;
 		}
@@ -66,12 +66,12 @@ function $Window($component){
 			case 13: // Enter (doesn't actually work in chrome because the button gets clicked immediately)
 				if($focused.is("button")){
 					$focused.addClass("pressed");
-					var release = function(){
+					var release = () => {
 						$focused.removeClass("pressed");
 						$focused.off("focusout", release);
 						$(window).off("keyup", keyup);
 					};
-					var keyup = function(e){
+					var keyup = e => {
 						if(e.keyCode === 32 || e.keyCode === 13){
 							release();
 						}
@@ -97,14 +97,14 @@ function $Window($component){
 		}
 	});
 	
-	$w.applyBounds = function(){
+	$w.applyBounds = () => {
 		$w.css({
 			left: Math.max(0, Math.min(innerWidth - $w.width(), $w[0].getBoundingClientRect().left)),
 			top: Math.max(0, Math.min(innerHeight - $w.height(), $w[0].getBoundingClientRect().top)),
 		});
 	};
 	
-	$w.center = function(){
+	$w.center = () => {
 		$w.css({
 			left: (innerWidth - $w.width()) / 2,
 			top: (innerHeight - $w.height()) / 2,
@@ -116,17 +116,17 @@ function $Window($component){
 	$G.on("resize", $w.applyBounds);
 	
 	var drag_offset_x, drag_offset_y;
-	var drag = function(e){
+	var drag = e => {
 		$w.css({
 			left: e.clientX - drag_offset_x,
 			top: e.clientY - drag_offset_y,
 		});
 	};
 	$w.$titlebar.attr("touch-action", "none");
-	$w.$titlebar.on("mousedown selectstart", function(e){
+	$w.$titlebar.on("mousedown selectstart", e => {
 		e.preventDefault();
 	});
-	$w.$titlebar.on("pointerdown", function(e){
+	$w.$titlebar.on("pointerdown", e => {
 		if($(e.target).is("button")){
 			return;
 		}
@@ -135,22 +135,22 @@ function $Window($component){
 		$G.on("pointermove", drag);
 		$("body").addClass("dragging");
 	});
-	$G.on("pointerup", function(e){
+	$G.on("pointerup", e => {
 		$w.applyBounds();
 		$G.off("pointermove", drag);
 		$("body").removeClass("dragging");
 	});
-	$w.$titlebar.on("dblclick", function(e){
+	$w.$titlebar.on("dblclick", e => {
 		if($component){
 			$component.dock();
 		}
 	});
 	
-	$w.$Button = function(text, handler){
+	$w.$Button = (text, handler) => {
 		var $b = $(E("button"))
 			.appendTo($w.$content)
 			.text(text)
-			.on("click", function(){
+			.on("click", () => {
 				if(handler){
 					handler();
 				}
@@ -158,7 +158,7 @@ function $Window($component){
 			});
 		return $b;
 	};
-	$w.title = function(title){
+	$w.title = title => {
 		if(title){
 			$w.$title.text(title);
 			return $w;
@@ -166,7 +166,7 @@ function $Window($component){
 			return $w.$title.text();
 		}
 	};
-	$w.close = function(){
+	$w.close = () => {
 		var e = $.Event("close");
 		$w.trigger(e);
 		if(e.isDefaultPrevented()){
@@ -195,9 +195,9 @@ function $FormWindow(title){
 	$w.$main = $(E("div")).appendTo($w.$form);
 	$w.$buttons = $(E("div")).appendTo($w.$form).addClass("button-group");
 	
-	$w.$Button = function(label, action){
+	$w.$Button = (label, action) => {
 		var $b = $(E("button")).appendTo($w.$buttons).text(label);
-		$b.on("click", function(e){
+		$b.on("click", e => {
 			// prevent the form from submitting
 			// @TODO: instead, prevent the form's submit event
 			e.preventDefault();
@@ -205,7 +205,7 @@ function $FormWindow(title){
 			action();
 		});
 		
-		$b.on("pointerdown", function(){
+		$b.on("pointerdown", () => {
 			$b[0].focus();
 		});
 		
diff --git a/src/OnCanvasSelection.js b/src/OnCanvasSelection.js
index bcc32c5..2b4ff21 100644
--- a/src/OnCanvasSelection.js
+++ b/src/OnCanvasSelection.js
@@ -7,7 +7,7 @@ class OnCanvasSelection extends OnCanvasObject {
 		sel.$el.addClass("selection");
 		var last_tool_transparent_mode = tool_transparent_mode;
 		var last_background_color = colors.background;
-		this._on_option_changed = function () {
+		this._on_option_changed = () => {
 			if (!sel.source_canvas) {
 				return;
 			}
@@ -68,7 +68,7 @@ class OnCanvasSelection extends OnCanvasObject {
 			}
 			sel.$el.append(sel.canvas);
 			sel.$handles = $Handles(sel.$el, sel.canvas, { outset: 2 });
-			sel.$el.on("user-resized", function (e, delta_x, delta_y, width, height) {
+			sel.$el.on("user-resized", (e, delta_x, delta_y, width, height) => {
 				sel.x += delta_x;
 				sel.y += delta_y;
 				sel.width = width;
@@ -77,7 +77,7 @@ class OnCanvasSelection extends OnCanvasObject {
 				sel.resize();
 			});
 			var mox, moy;
-			var pointermove = function (e) {
+			var pointermove = e => {
 				var m = e2c(e);
 				sel.x = Math.max(Math.min(m.x - mox, canvas.width), -sel.width);
 				sel.y = Math.max(Math.min(m.y - moy, canvas.height), -sel.height);
@@ -86,7 +86,7 @@ class OnCanvasSelection extends OnCanvasObject {
 					sel.draw();
 				}
 			};
-			sel.canvas_pointerdown = function (e) {
+			sel.canvas_pointerdown = e => {
 				e.preventDefault();
 				var rect = sel.canvas.getBoundingClientRect();
 				var cx = e.clientX - rect.left;
@@ -94,7 +94,7 @@ class OnCanvasSelection extends OnCanvasObject {
 				mox = ~~(cx / rect.width * sel.canvas.width);
 				moy = ~~(cy / rect.height * sel.canvas.height);
 				$G.on("pointermove", pointermove);
-				$G.one("pointerup", function () {
+				$G.one("pointerup", () => {
 					$G.off("pointermove", pointermove);
 				});
 				if (e.shiftKey) {
@@ -258,7 +258,7 @@ class OnCanvasSelection extends OnCanvasObject {
 		var sel = this;
 		sel.instantiate(null, "passive");
 		if (sel.canvas) {
-			undoable(0, function () {
+			undoable(0, () => {
 				ctx.copy(sel.canvas);
 				$canvas_area.trigger("resize");
 			});
diff --git a/src/OnCanvasTextBox.js b/src/OnCanvasTextBox.js
index 06a0507..1e29049 100644
--- a/src/OnCanvasTextBox.js
+++ b/src/OnCanvasTextBox.js
@@ -6,7 +6,7 @@ class OnCanvasTextBox extends OnCanvasObject {
 		var tb = this;
 		tb.$el.addClass("textbox");
 		tb.$editor = $(E("textarea")).addClass("textbox-editor");
-		var update = function () {
+		var update = () => {
 			var font = text_tool_font;
 			font.color = colors.foreground;
 			font.background = tool_transparent_mode ? "transparent" : colors.background;
@@ -63,7 +63,7 @@ class OnCanvasTextBox extends OnCanvasObject {
 			tb.$el.append(tb.$editor);
 			tb.$editor[0].focus();
 			tb.$handles = $Handles(tb.$el, tb.$editor[0], { outset: 2 });
-			tb.$el.on("user-resized", function (e, delta_x, delta_y, width, height) {
+			tb.$el.on("user-resized", (e, delta_x, delta_y, width, height) => {
 				tb.x += delta_x;
 				tb.y += delta_y;
 				tb.width = width;
@@ -71,7 +71,7 @@ class OnCanvasTextBox extends OnCanvasObject {
 				tb.position();
 			});
 			var mox, moy;
-			var pointermove = function (e) {
+			var pointermove = e => {
 				var m = e2c(e);
 				tb.x = Math.max(Math.min(m.x - mox, canvas.width), -tb.width);
 				tb.y = Math.max(Math.min(m.y - moy, canvas.height), -tb.height);
@@ -80,7 +80,7 @@ class OnCanvasTextBox extends OnCanvasObject {
 					tb.draw();
 				}
 			};
-			tb.$el.on("pointerdown", function (e) {
+			tb.$el.on("pointerdown", e => {
 				if (e.target instanceof HTMLInputElement ||
 					e.target instanceof HTMLTextAreaElement ||
 					e.target.classList.contains("handle")) {
@@ -93,7 +93,7 @@ class OnCanvasTextBox extends OnCanvasObject {
 				mox = ~~(cx);
 				moy = ~~(cy);
 				$G.on("pointermove", pointermove);
-				$G.one("pointerup", function () {
+				$G.one("pointerup", () => {
 					$G.off("pointermove", pointermove);
 				});
 			});
@@ -106,7 +106,7 @@ class OnCanvasTextBox extends OnCanvasObject {
 		var tb = this;
 		var text = tb.$editor.val();
 		if (text) {
-			undoable(0, function () {
+			undoable(0, () => {
 				var font = text_tool_font;
 				ctx.fillStyle = font.background;
 				ctx.fillRect(tb.x, tb.y, tb.width, tb.height);
diff --git a/src/app.js b/src/app.js
index ba37147..ef61d21 100644
--- a/src/app.js
+++ b/src/app.js
@@ -92,7 +92,7 @@ var $status_text = $(E("div")).addClass("status-text").appendTo($status_area);
 var $status_position = $(E("div")).addClass("status-coordinates").appendTo($status_area);
 var $status_size = $(E("div")).addClass("status-coordinates").appendTo($status_area);
 
-$status_text.default = function(){
+$status_text.default = () => {
 	$status_text.text("For Help, click Help Topics on the Help Menu.");
 };
 $status_text.default();
@@ -115,10 +115,10 @@ if(menu_bar_outside_frame){
 	$menu_bar.prependTo($V);
 }
 
-$menu_bar.on("info", function(e, info){
+$menu_bar.on("info", (e, info) => {
 	$status_text.text(info);
 });
-$menu_bar.on("default-info", function(e){
+$menu_bar.on("default-info", e => {
 	$status_text.default();
 });
 
@@ -145,8 +145,8 @@ var $toolbox = $ToolBox(tools);
 // so it can display names of the tools, and maybe authors and previews (and not necessarily icons)
 var $colorbox = $ColorBox();
 
-$canvas.on("user-resized", function(e, _x, _y, width, height){
-	undoable(0, function(){
+$canvas.on("user-resized", (e, _x, _y, width, height) => {
+	undoable(0, () => {
 		canvas.width = Math.max(1, width);
 		canvas.height = Math.max(1, height);
 		ctx.disable_image_smoothing();
@@ -167,30 +167,30 @@ $canvas.on("user-resized", function(e, _x, _y, width, height){
 		storage.set({
 			width: canvas.width,
 			height: canvas.height,
-		}, function(err){
+		}, err => {
 			// oh well
 		})
 	});
 });
 
-$G.on("resize", function(){ // for browser zoom, and in-app zoom of the canvas
+$G.on("resize", () => { // for browser zoom, and in-app zoom of the canvas
 	update_canvas_rect();
 	update_disable_aa();
 });
-$canvas_area.on("scroll", function() {
+$canvas_area.on("scroll", () => {
 	update_canvas_rect();
 });
-$canvas_area.on("resize", function() {
+$canvas_area.on("resize", () => {
 	update_magnified_canvas_size();
 });
 
-$("body").on("dragover dragenter", function(e){
+$("body").on("dragover dragenter", e => {
 	var dt = e.originalEvent.dataTransfer;
 	var has_files = Array.from(dt.types).indexOf("Files") !== -1;
 	if(has_files){
 		e.preventDefault();
 	}
-}).on("drop", function(e){
+}).on("drop", e => {
 	if(e.isDefaultPrevented()){
 		return;
 	}
@@ -205,10 +205,10 @@ $("body").on("dragover dragenter", function(e){
 });
 
 var keys = {};
-$G.on("keyup", function(e){
+$G.on("keyup", e => {
 	delete keys[e.keyCode];
 });
-$G.on("keydown", function(e){
+$G.on("keydown", e => {
 	if(e.isDefaultPrevented()){
 		return;
 	}
@@ -229,7 +229,7 @@ $G.on("keydown", function(e){
 	// probably best to use a library at this point!
 	
 	if(selection){
-		var nudge_selection = function(delta_x, delta_y){
+		var nudge_selection = (delta_x, delta_y) => {
 			selection.x += delta_x;
 			selection.y += delta_y;
 			selection.position();
@@ -361,7 +361,7 @@ $G.on("keydown", function(e){
 		e.preventDefault();
 	}
 });
-$G.on("cut copy paste", function(e){
+$G.on("cut copy paste", e => {
 	if(e.isDefaultPrevented()){
 		return;
 	}
@@ -380,7 +380,7 @@ $G.on("cut copy paste", function(e){
 
 	if(e.type === "copy" || e.type === "cut"){
 		if(selection && selection.canvas){
-			var do_sync_clipboard_copy_or_cut = function() {
+			var do_sync_clipboard_copy_or_cut = () => {
 				// works only for pasting within a jspaint instance
 				var data_url = selection.canvas.toDataURL();
 				cd.setData("text/x-data-uri; type=image/png", data_url);
@@ -404,12 +404,12 @@ $G.on("cut copy paste", function(e){
 			}
 		}
 	}else if(e.type === "paste"){
-		$.each(cd.items, function(i, item){
+		$.each(cd.items, (i, item) => {
 			if(item.type.match(/^text\/(?:x-data-uri|uri-list|plain)|URL$/)){
-				item.getAsString(function(text){
+				item.getAsString(text => {
 					var uris = get_URIs(text);
 					if (uris.length > 0) {
-						load_image_from_URI(uris[0], function(err, img){
+						load_image_from_URI(uris[0], (err, img) => {
 							if(err){ return show_resource_load_error_message(); }
 							paste(img);
 						});
@@ -434,7 +434,7 @@ set_magnification(1);
 storage.get({
 	width: default_canvas_width,
 	height: default_canvas_height,
-}, function(err, values){
+}, (err, values) => {
 	if(err){return;}
 	my_canvas_width = values.width;
 	my_canvas_height = values.height;
@@ -449,7 +449,7 @@ storage.get({
 });
 
 if(window.document_file_path_to_open){
-	open_from_file_path(document_file_path_to_open, function(err){
+	open_from_file_path(document_file_path_to_open, err => {
 		if(err){
 			return show_error_message("Failed to open file " + document_file_path_to_open, err);
 		}
@@ -520,7 +520,7 @@ function tool_go(selected_tool, event_name){
 	if(selected_tool.paint){
 		if(selected_tool.continuous === "space"){
 			var ham = brush_shape.match(/diagonal/) ? brosandham_line : bresenham_line;
-			ham(pointer_previous.x, pointer_previous.y, pointer.x, pointer.y, function(x, y){
+			ham(pointer_previous.x, pointer_previous.y, pointer.x, pointer.y, (x, y) => {
 				selected_tool.paint(ctx, x, y);
 			});
 		}else{
@@ -582,11 +582,11 @@ function canvas_pointer_move(e){
 	});
 	pointer_previous = pointer;
 }
-$canvas.on("pointermove", function(e){
+$canvas.on("pointermove", e => {
 	pointer = e2c(e);
 	$status_position.text(pointer.x + "," + pointer.y);
 });
-$canvas.on("pointerenter", function(e){
+$canvas.on("pointerenter", e => {
 	pointer_over_canvas = true;
 
 	update_helper_layer();
@@ -596,7 +596,7 @@ $canvas.on("pointerenter", function(e){
 		update_helper_layer_on_pointermove_active = true;
 	}
 });
-$canvas.on("pointerleave", function(e){
+$canvas.on("pointerleave", e => {
 	pointer_over_canvas = false;
 
 	$status_position.text("");
@@ -612,7 +612,7 @@ $canvas.on("pointerleave", function(e){
 var pointer_active = false;
 var pointer_over_canvas = false;
 var update_helper_layer_on_pointermove_active = false;
-$canvas.on("pointerdown", function(e){
+$canvas.on("pointerdown", e => {
 	update_canvas_rect();
 
 	// Quick Undo when there are multiple pointers (i.e. for touch)
@@ -626,7 +626,7 @@ $canvas.on("pointerdown", function(e){
 	pointer_active = true;
 	pointer_type = e.pointerType;
 	pointer_buttons = e.buttons;
-	$G.one("pointerup", function(e){
+	$G.one("pointerup", e => {
 		pointer_active = false;
 		update_helper_layer();
 		
@@ -649,7 +649,7 @@ $canvas.on("pointerdown", function(e){
 	shift = e.shiftKey;
 	pointer_start = pointer_previous = pointer = e2c(e);
 
-	var pointerdown_action = function(){
+	var pointerdown_action = () => {
 	// TODO for multitools: don't register event listeners for each tool
 	selected_tools.forEach((selected_tool)=> {
 
@@ -661,7 +661,7 @@ $canvas.on("pointerdown", function(e){
 		if(selected_tool.continuous === "time"){
 			var iid = setInterval(()=> { tool_go(selected_tool); }, 5);
 		}
-		$G.one("pointerup", function(e, canceling){
+		$G.one("pointerup", (e, canceling) => {
 			button = undefined;
 			reverse = false;
 			if(canceling){
@@ -692,7 +692,7 @@ $canvas.on("pointerdown", function(e){
 	update_helper_layer();
 });
 
-$canvas_area.on("pointerdown", function(e){
+$canvas_area.on("pointerdown", e => {
 	if(e.button === 0){
 		if($canvas_area.is(e.target)){
 			if(selection){
@@ -706,7 +706,7 @@ $app
 .add($toolbox)
 // .add($toolbox2)
 .add($colorbox)
-.on("mousedown selectstart contextmenu", function(e){
+.on("mousedown selectstart contextmenu", e => {
 	if(e.isDefaultPrevented()){
 		return;
 	}
@@ -729,6 +729,6 @@ $app
 });
 
 // Stop drawing (or dragging or whatver) if you Alt+Tab or whatever
-$G.on("blur", function(e){
+$G.on("blur", e => {
 	$G.triggerHandler("pointerup");
 });
diff --git a/src/canvas-change.js b/src/canvas-change.js
index 8ef0292..5bd0f24 100644
--- a/src/canvas-change.js
+++ b/src/canvas-change.js
@@ -1,12 +1,12 @@
 
-(function(){
+(() => {
 	
-	var may_be_changed = function(){
+	var may_be_changed = () => {
 		window.console && console.log("change may have occured");
 		$canvas.triggerHandler("change");
 	};
 	
-	var debug_event = function(e, synthetic){
+	var debug_event = (e, synthetic) => {
 		// var label = synthetic ? "(synthetic)" : "(normal)";
 		// window.console && console.debug && console.debug(e.type, label);
 	};
@@ -15,7 +15,7 @@
 	
 	$canvas.on("user-resized.ugly-hook", may_be_changed);
 	
-	$canvas_area.on("pointerdown.ugly-hook", "*", function(e, synthetic){
+	$canvas_area.on("pointerdown.ugly-hook", "*", (e, synthetic) => {
 		debug_event(e, synthetic);
 		if(synthetic){ return; }
 		
@@ -29,14 +29,14 @@
 		}else{
 			// Changes may occur when you release
 			pointer_operations = [e];
-			var pointermove = function(e, synthetic){
+			var pointermove = (e, synthetic) => {
 				debug_event(e, synthetic);
 				if(synthetic){ return; }
 				
 				pointer_operations.push(e);
 			};
 			$G.on("pointermove.ugly-hook", pointermove);
-			$G.one("pointerup.ugly-hook", function(e, synthetic){
+			$G.one("pointerup.ugly-hook", (e, synthetic) => {
 				debug_event(e, synthetic);
 				if(synthetic){ return; }
 				
@@ -47,8 +47,8 @@
 		}
 	});
 
-	$G.on("session-update.ugly-hook", function(){
+	$G.on("session-update.ugly-hook", () => {
 		setTimeout(may_be_changed);
 	});
 
-}());
+})();
diff --git a/src/electron-injected.js b/src/electron-injected.js
index 514759b..949d0eb 100644
--- a/src/electron-injected.js
+++ b/src/electron-injected.js
@@ -21,7 +21,7 @@ var reg_contents = `Windows Registry Editor Version 5.00
 `; // oof \\\\
 var reg_file_path = path.join(is_dev ? "." : path.dirname(argv[0]), `set-jspaint${is_dev ? "-DEV-MODE" : ""}-as-default-image-editor.reg`);
 if(process.platform == "win32" && !is_dev){
-	fs.writeFile(reg_file_path, reg_contents, function(err){
+	fs.writeFile(reg_file_path, reg_contents, err => {
 		if(err){
 			return console.error(err);
 		}
@@ -36,8 +36,8 @@ if (process.platform == "win32" && argv.length >= 2) {
 	}
 }
 
-window.open_from_file_path = function(file_path, callback, canceled){
-	fs.readFile(file_path, function(err, buffer) {
+window.open_from_file_path = (file_path, callback, canceled) => {
+	fs.readFile(file_path, (err, buffer) => {
 		if(err){
 			return callback(err);
 		}
@@ -51,7 +51,7 @@ window.open_from_file_path = function(file_path, callback, canceled){
 	});
 };
 
-window.save_to_file_path = function(filePath, formatName, savedCallback){
+window.save_to_file_path = (filePath, formatName, savedCallback) => {
 	var mimeType = {
 		"JPEG": "image/jpeg",
 		"PNG": "image/png",
@@ -68,16 +68,16 @@ window.save_to_file_path = function(filePath, formatName, savedCallback){
 	// if(mimeType === "image/gif"){
 	// 	new GIF();
 	// }
-	canvas.toBlob(function(blob){
+	canvas.toBlob(blob => {
 		if(blob.type !== mimeType){
 			return show_error_message("Failed to save as " + formatName + " (your browser doesn't support exporting a canvas as \"" + mimeType + "\")");
 		}
-		sanity_check_blob(blob, function(){
-			blob_to_buffer(blob, function(err, buffer){
+		sanity_check_blob(blob, () => {
+			blob_to_buffer(blob, (err, buffer) => {
 				if(err){
 					return show_error_message("Failed to save! (Technically, failed to convert a Blob to a Buffer.)", err);
 				}
-				fs.writeFile(filePath, buffer, function(err){
+				fs.writeFile(filePath, buffer, err => {
 					if(err){
 						return show_error_message("Failed to save file!", err);
 					}
@@ -90,8 +90,8 @@ window.save_to_file_path = function(filePath, formatName, savedCallback){
 };
 
 // TODO: window.platform.saveCanvasAs etc. or platformIntegration or system or something
-window.systemSaveCanvasAs = function(canvas, suggestedFileName, savedCallback){
-	var getExtension = function(filePathOrName){
+window.systemSaveCanvasAs = (canvas, suggestedFileName, savedCallback) => {
+	var getExtension = filePathOrName => {
 		var splitByDots = filePathOrName.split(/\./g);
 		return splitByDots[splitByDots.length - 1].toLowerCase();
 	};
@@ -116,7 +116,7 @@ window.systemSaveCanvasAs = function(canvas, suggestedFileName, savedCallback){
 	dialog.showSaveDialog({
 		defaultPath: suggestedFileName,
 		filters: filters,
-	}, function(filePath) {
+	}, filePath => {
 		if(!filePath){
 			return; // user canceled
 		}
@@ -125,7 +125,7 @@ window.systemSaveCanvasAs = function(canvas, suggestedFileName, savedCallback){
 			// TODO: Linux/Unix?? you're not supposed to need file extensions
 			return show_error_message("Missing file extension - try adding .png to the file name");
 		}
-		var formatNameMatched = ((filters.find(function(filter){return filter.extensions.indexOf(extension) > -1})) || {}).name;
+		var formatNameMatched = ((filters.find(filter => {return filter.extensions.indexOf(extension) > -1})) || {}).name;
 		if(!formatNameMatched){
 			return show_error_message("Can't save as *." +extension + " - try adding .png to the file name");
 		}
@@ -134,7 +134,7 @@ window.systemSaveCanvasAs = function(canvas, suggestedFileName, savedCallback){
 	});
 };
 
-window.systemSetAsWallpaperCentered = function(c){
+window.systemSetAsWallpaperCentered = c => {
 	var dataPath = require('electron').remote.app.getPath("userData");
 
 	var imgPath = require("path").join(dataPath, "bg.png");
@@ -153,14 +153,14 @@ window.systemSetAsWallpaperCentered = function(c){
 		wallpaperCanvas.ctx.drawImage(c, ~~x, ~~y);
 	}
 
-	get_array_buffer_from_canvas(wallpaperCanvas).then(function(array_buffer){
+	get_array_buffer_from_canvas(wallpaperCanvas).then(array_buffer => {
 		var buffer = new Buffer(array_buffer);
-		fs.writeFile(imgPath, buffer, function(err){
+		fs.writeFile(imgPath, buffer, err => {
 			if(err){
 				return show_error_message("Failed to set as desktop background: couldn't write temporary image file.", err);
 			}
 			// {scale: "center"} only supported on macOS; see above workaround
-			wallpaper.set(imgPath, {scale: "center"}, function(err){
+			wallpaper.set(imgPath, {scale: "center"}, err => {
 				if(err){
 					show_error_message("Failed to set as desktop background!", err);
 				}
diff --git a/src/electron-main.js b/src/electron-main.js
index 2e95f17..8bbd437 100644
--- a/src/electron-main.js
+++ b/src/electron-main.js
@@ -50,7 +50,7 @@ const createWindow = () => {
     mainWindow = null;
   });
 
-  const handleRedirect = function(e, url) {
+  const handleRedirect = (e, url) => {
     // check that the URL is not part of the app
     if(url.indexOf("file://") === -1){
       e.preventDefault();
diff --git a/src/extra-tools.js b/src/extra-tools.js
index db1844d..41ee84c 100644
--- a/src/extra-tools.js
+++ b/src/extra-tools.js
@@ -27,7 +27,7 @@ extra_tools = [{
 			this.rendered_size = brush_size;
 			this.rendered_shape = brush_shape;
 		}
-		var draw_brush = function(x, y){
+		var draw_brush = (x, y) => {
 			ctx.drawImage(brush_canvas, Math.ceil(x-csz/2), Math.ceil(y-csz/2));
 		};
 		var r = airbrush_size * 2;
@@ -83,7 +83,7 @@ extra_tools = [{
 			this.rendered_size = brush_size;
 			this.rendered_shape = brush_shape;
 		}
-		var draw_brush = function(x, y){
+		var draw_brush = (x, y) => {
 			ctx.drawImage(brush_canvas, Math.ceil(x-csz/2), Math.ceil(y-csz/2));
 		};
 		for(var i = 0; i < 60; i++){
diff --git a/src/functions.js b/src/functions.js
index dd12281..6f1fabb 100644
--- a/src/functions.js
+++ b/src/functions.js
@@ -156,7 +156,7 @@ function show_custom_zoom_window() {
 	var $really_custom_radio_option = $fieldset.find("input[value='really-custom']");
 	var $really_custom_input = $fieldset.find("input[name='really-custom-zoom-input']");
 
-	$really_custom_input.closest("label").on("click", function(e){
+	$really_custom_input.closest("label").on("click", e => {
 		$really_custom_radio_option.prop("checked", true);
 		$really_custom_input[0].focus();
 	});
@@ -168,7 +168,7 @@ function show_custom_zoom_window() {
 
 	$fieldset.find("label").css({display: "block"});
 
-	$w.$Button("Okay", function(){
+	$w.$Button("Okay", () => {
 		var option_val = $fieldset.find("input[name='custom-zoom-radio']:checked").val();
 		var mag;
 		if(option_val === "really-custom"){
@@ -181,7 +181,7 @@ function show_custom_zoom_window() {
 			if(isNaN(mag)){
 				var $msgw = new $FormWindow("Invalid Value").addClass("dialogue-window");
 				$msgw.$main.text("The value specified for custom zoom was invalid.");
-				$msgw.$Button("Okay", function(){
+				$msgw.$Button("Okay", () => {
 					$msgw.close();
 				});
 				return;
@@ -194,7 +194,7 @@ function show_custom_zoom_window() {
 
 		$w.close();
 	})[0].focus();
-	$w.$Button("Cancel", function(){
+	$w.$Button("Cancel", () => {
 		$w.close();
 	});
 
@@ -255,13 +255,13 @@ function create_and_trigger_input(attrs, callback){
 // TODO: rename these functions to lowercase (and maybe say "files" in this case)
 function get_FileList_from_file_select_dialog(callback){
 	// TODO: specify mime types?
-	create_and_trigger_input({type: "file"}, function(input){
+	create_and_trigger_input({type: "file"}, input => {
 		callback(input.files);
 	});
 }
 
 function open_from_Image(img, callback, canceled){
-	are_you_sure(function(){
+	are_you_sure(() => {
 		// TODO: shouldn't open_from_* start a new session?
 
 		this_ones_a_frame_changer();
@@ -281,7 +281,7 @@ function open_from_Image(img, callback, canceled){
 function get_URIs(text) {
 	// parse text/uri-list
 	// get lines, discarding comments
-	var lines = text.split(/[\n\r]+/).filter(function(line){return line[0] !== "#" && line});
+	var lines = text.split(/[\n\r]+/).filter(line => {return line[0] !== "#" && line});
 	// discard text with too many lines (likely pasted HTML or something) - may want to revisit this
 	if (lines.length > 15) {
 		return [];
@@ -300,9 +300,9 @@ function get_URIs(text) {
 function load_image_from_URI(uri, callback){
 	// TODO: if URI is not blob: or data:, show dialog with progress bar and this string from mspaint.exe: "Downloading picture"
 	fetch(uri)
-	.then(function(response) {
+	.then(response => {
 		return response.blob();
-	}).then(function(blob) {
+	}).then(blob => {
 		var img = new Image();
 		img.crossOrigin = "Anonymous";
 		img.onload = function(){
@@ -311,28 +311,28 @@ function load_image_from_URI(uri, callback){
 			}
 			callback(null, img);
 		};
-		img.onerror = function(e) {
+		img.onerror = e => {
 			callback && callback(new Error("Image failed to load"));
 		};
 		img.src = window.URL.createObjectURL(blob);
-	}).catch(function(exception) {
+	}).catch(exception => {
 		callback && callback(new Error("Image failed to load"));
 	});
 }
 function open_from_URI(uri, callback, canceled){
-	load_image_from_URI(uri, function(err, img){
+	load_image_from_URI(uri, (err, img) => {
 		if(err){ return callback(err); }
 		open_from_Image(img, callback, canceled);
 	});
 }
 function open_from_File(file, callback, canceled){
 	var blob_url = URL.createObjectURL(file);
-	load_image_from_URI(blob_url, function(err, img){
+	load_image_from_URI(blob_url, (err, img) => {
 		// revoke object URL regardless of error
 		URL.revokeObjectURL(file);
 		if(err){ return callback(err); }
 
-		open_from_Image(img, function(){
+		open_from_Image(img, () => {
 			file_name = file.name;
 			document_file_path = file.path; // available in Electron
 			update_title();
@@ -357,14 +357,14 @@ function get_image_file_from_FileList_or_show_error(files, user_input_method_ver
 function open_from_FileList(files, user_input_method_verb_past_tense){
 	var file = get_image_file_from_FileList_or_show_error(files, user_input_method_verb_past_tense);
 	if(file){
-		open_from_File(file, function(err){
+		open_from_File(file, err => {
 			if(err){ return show_error_message("Failed to open file:", err); }
 		});
 	}
 }
 
 function file_new(){
-	are_you_sure(function(){
+	are_you_sure(() => {
 		this_ones_a_frame_changer();
 
 		reset_file();
@@ -379,7 +379,7 @@ function file_new(){
 // there's this little thing called Inversion of Control...
 // also paste_from_file_select_dialog
 function file_open(){
-	get_FileList_from_file_select_dialog(function(files){
+	get_FileList_from_file_select_dialog(files => {
 		open_from_FileList(files, "selected");
 	});
 }
@@ -395,7 +395,7 @@ function file_load_from_url(){
 	// TODO: URL validation (input has to be in a form (and we don't want the form to submit))
 	$w.$main.html("<label>URL: <input type='url' required value='' class='url-input'/></label>");
 	var $input = $w.$main.find(".url-input");
-	$w.$Button("Load", function(){
+	$w.$Button("Load", () => {
 		var uris = get_URIs($input.val());
 		if (uris.length > 0) {
 			// TODO: retry loading if same URL entered
@@ -408,7 +408,7 @@ function file_load_from_url(){
 			show_error_message("Invalid URL. It must include a protocol (https:// or http://)");
 		}
 	});
-	$w.$Button("Cancel", function(){
+	$w.$Button("Cancel", () => {
 		$w.close();
 	});
 	$w.center();
@@ -424,7 +424,7 @@ function file_save(){
 	}
 	if(document_file_path){
 		// TODO: save as JPEG by default if the previously opened/saved file was a JPEG?
-		return save_to_file_path(document_file_path, "PNG", function(saved_file_path, saved_file_name){
+		return save_to_file_path(document_file_path, "PNG", (saved_file_path, saved_file_name) => {
 			saved = true;
 			document_file_path = saved_file_path;
 			file_name = saved_file_name;
@@ -436,7 +436,7 @@ function file_save(){
 
 function file_save_as(){
 	deselect();
-	save_canvas_as(canvas, file_name.replace(/\.(bmp|dib|a?png|gif|jpe?g|jpe|jfif|tiff?|webp|raw)$/, "") + ".png", function(saved_file_path, saved_file_name){
+	save_canvas_as(canvas, file_name.replace(/\.(bmp|dib|a?png|gif|jpe?g|jpe|jfif|tiff?|webp|raw)$/, "") + ".png", (saved_file_path, saved_file_name) => {
 		saved = true;
 		document_file_path = saved_file_path;
 		file_name = saved_file_name;
@@ -452,20 +452,20 @@ function are_you_sure(action, canceled){
 		var $w = new $FormWindow().addClass("dialogue-window");
 		$w.title("Paint");
 		$w.$main.text("Save changes to "+file_name+"?");
-		$w.$Button("Save", function(){
+		$w.$Button("Save", () => {
 			$w.close();
 			file_save();
 			action();
 		})[0].focus();
-		$w.$Button("Discard", function(){
+		$w.$Button("Discard", () => {
 			$w.close();
 			action();
 		});
-		$w.$Button("Cancel", function(){
+		$w.$Button("Cancel", () => {
 			$w.close();
 			canceled && canceled();
 		});
-		$w.$x.on("click", function(){
+		$w.$x.on("click", () => {
 			canceled && canceled();
 		});
 		$w.center();
@@ -490,7 +490,7 @@ function show_error_message(message, error){
 			overflow: "auto",
 		});
 	}
-	$w.$Button("OK", function(){
+	$w.$Button("OK", () => {
 		$w.close();
 	});
 	$w.center();
@@ -510,7 +510,7 @@ function show_resource_load_error_message(){
 		", such as <a href='https://imgur.com/'>Imgur</a>."
 	);
 	$w.$main.css({maxWidth: "500px"});
-	$w.$Button("OK", function(){
+	$w.$Button("OK", () => {
 		$w.close();
 	});
 	$w.center();
@@ -664,7 +664,7 @@ function paste_image_from_file(file){
 	// TODO: revoke object URL
 	var blob_url = URL.createObjectURL(file);
 	// paste_image_from_URI(blob_url);
-	load_image_from_URI(blob_url, function(err, img){
+	load_image_from_URI(blob_url, (err, img) => {
 		// TODO: this shouldn't really have the CORS error message, if it's from a blob URI
 		if(err){ return show_resource_load_error_message(); }
 		paste(img);
@@ -674,7 +674,7 @@ function paste_image_from_file(file){
 }
 
 function paste_from_file_select_dialog(){
-	get_FileList_from_file_select_dialog(function(files){
+	get_FileList_from_file_select_dialog(files => {
 		var file = get_image_file_from_FileList_or_show_error(files, "selected");
 		if(file){
 			paste_image_from_file(file);
@@ -691,10 +691,10 @@ function paste(img){
 			"The image is bigger than the canvas.<br>" +
 			"Would you like the canvas to be enlarged?<br>"
 		);
-		$w.$Button("Enlarge", function(){
+		$w.$Button("Enlarge", () => {
 			$w.close();
 			// Additional undoable
-			undoable(function(){
+			undoable(() => {
 				var original = undos[undos.length-1];
 				canvas.width = Math.max(original.width, img.width);
 				canvas.height = Math.max(original.height, img.height);
@@ -708,11 +708,11 @@ function paste(img){
 				$canvas_area.trigger("resize");
 			});
 		})[0].focus();
-		$w.$Button("Crop", function(){
+		$w.$Button("Crop", () => {
 			$w.close();
 			do_the_paste();
 		});
-		$w.$Button("Cancel", function(){
+		$w.$Button("Cancel", () => {
 			$w.close();
 		});
 		$w.center();
@@ -744,11 +744,11 @@ function render_history_as_gif(){
 	});
 	$win.$main.css({padding: 5});
 
-	var $cancel = $win.$Button('Cancel', function(){
+	var $cancel = $win.$Button('Cancel', () => {
 		$win.close();
 	});
 
-	$win.on('close', function(){
+	$win.on('close', () => {
 		gif.abort();
 	});
 
@@ -762,12 +762,12 @@ function render_history_as_gif(){
 			height: height,
 		});
 
-		gif.on("progress", function(p){
+		gif.on("progress", p => {
 			$progress.val(p);
 			$progress_percent.text(~~(p*100)+"%");
 		});
 
-		gif.on("finished", function(blob){
+		gif.on("finished", blob => {
 			$win.title("Rendered GIF");
 			var url = URL.createObjectURL(blob);
 			$output.empty().append(
@@ -777,15 +777,15 @@ function render_history_as_gif(){
 					height: height,
 				})
 			);
-			$win.$Button("Upload to Imgur", function(){
+			$win.$Button("Upload to Imgur", () => {
 				$win.close();
-				sanity_check_blob(blob, function(){
+				sanity_check_blob(blob, () => {
 					show_imgur_uploader(blob);
 				});
 			});
-			$win.$Button("Save", function(){
+			$win.$Button("Save", () => {
 				$win.close();
-				sanity_check_blob(blob, function(){
+				sanity_check_blob(blob, () => {
 					saveAs(blob, file_name.replace(/\.(bmp|dib|a?png|gif|jpe?g|jpe|jfif|tiff?|webp|raw)$/, "") + " history.gif");
 				});
 			});
@@ -872,12 +872,12 @@ function undoable(callback, action){
 		var $w = new $FormWindow().addClass("dialogue-window");
 		$w.title("Paint");
 		$w.$main.html("Discard "+redos.length+" possible redo-able actions?<br>(Ctrl+Y or Ctrl+Shift+Z to redo)<br>");
-		$w.$Button(action ? "Discard and Apply" : "Discard", function(){
+		$w.$Button(action ? "Discard and Apply" : "Discard", () => {
 			$w.close();
 			redos = [];
 			action && action();
 		})[0].focus();
-		$w.$Button("Keep", function(){
+		$w.$Button("Keep", () => {
 			$w.close();
 		});
 		$w.center();
@@ -1009,16 +1009,16 @@ async function edit_copy(execCommandFallback){
 				throw new Error("The Async Clipboard API is not supported by this browser. " + browserRecommendationForClipboardAccess);
 			}
 		}
-		selection.canvas.toBlob(function(blob) {
-			sanity_check_blob(blob, function(){
+		selection.canvas.toBlob(blob => {
+			sanity_check_blob(blob, () => {
 				navigator.clipboard.write([
 					new ClipboardItem(Object.defineProperty({}, blob.type, {
 						value: blob,
 						enumerable: true,
 					}))
-				]).then(function(){
+				]).then(() => {
 					console.log("Copied image to the clipboard");
-				}, function(error){
+				}, error => {
 					show_error_message("Failed to copy to the Clipboard.", error);
 				});
 			});
@@ -1072,7 +1072,7 @@ async function edit_paste(execCommandFallback){
 				if(clipboardText) {
 					var uris = get_URIs(clipboardText);
 					if (uris.length > 0) {
-						load_image_from_URI(uris[0], function(err, img){
+						load_image_from_URI(uris[0], (err, img) => {
 							if(err){ return show_resource_load_error_message(); }
 							paste(img);
 						});
@@ -1092,7 +1092,7 @@ async function edit_paste(execCommandFallback){
 }
 
 function image_invert(){
-	apply_image_transformation(function(original_canvas, original_ctx, new_canvas, new_ctx){
+	apply_image_transformation((original_canvas, original_ctx, new_canvas, new_ctx) => {
 		var id = original_ctx.getImageData(0, 0, original_canvas.width, original_canvas.height);
 		for(var i=0; i<id.data.length; i+=4){
 			id.data[i+0] = 255 - id.data[i+0];
@@ -1104,7 +1104,7 @@ function image_invert(){
 }
 
 function clear(){
-	undoable(0, function(){
+	undoable(0, () => {
 		this_ones_a_frame_changer();
 
 		if(transparency){
@@ -1203,7 +1203,7 @@ function detect_transparency(){
 
 function make_monochrome_pattern(lightness){
 
-	var dither_threshold_table = Array.from({length: 64}, function(undef, p){
+	var dither_threshold_table = Array.from({length: 64}, (undef, p) => {
 		var q = p ^ (p >> 3);
 		return (
 			((p & 4) >> 2) | ((q & 4) >> 1) |
@@ -1313,7 +1313,7 @@ function image_attributes(){
 	$units.append('<label><input type="radio" name="units" value="cm">Cm</label>');
 	$units.append('<label><input type="radio" name="units" value="px">Pixels</label>');
 	$units.find("[value=" + current_unit + "]").attr({checked: true});
-	$units.on("change", function(){
+	$units.on("change", () => {
 		var new_unit = $units.find(":checked").val();
 		$width.val(width_in_px / unit_sizes_in_px[new_unit]);
 		$height.val(height_in_px / unit_sizes_in_px[new_unit]);
@@ -1332,7 +1332,7 @@ function image_attributes(){
 
 	// Buttons on the right
 
-	$w.$Button("Okay", function(){
+	$w.$Button("Okay", () => {
 		var transparency_option = $transparency.find(":checked").val();
 		var colors_option = $colors.find(":checked").val();
 		var unit = $units.find(":checked").val();
@@ -1363,11 +1363,11 @@ function image_attributes(){
 		image_attributes.$window.close();
 	})[0].focus();
 
-	$w.$Button("Cancel", function(){
+	$w.$Button("Cancel", () => {
 		image_attributes.$window.close();
 	});
 
-	$w.$Button("Default", function(){
+	$w.$Button("Default", () => {
 		width_in_px = default_canvas_width;
 		height_in_px = default_canvas_height;
 		$width.val(width_in_px / unit_sizes_in_px[current_unit]);
@@ -1396,7 +1396,7 @@ function image_flip_and_rotate(){
 	$rotate_by_angle.append("<label><input type='radio' name='rotate-by-angle' value='arbitrary'/><input type='number' min='-360' max='360' name='rotate-by-arbitrary-angle' value=''/> Degrees</label>");
 	$rotate_by_angle.find("input").attr({disabled: true});
 
-	$fieldset.find("input").on("change", function(){
+	$fieldset.find("input").on("change", () => {
 		var action = $fieldset.find("input[name='flip-or-rotate']:checked").val();
 		$rotate_by_angle.find("input").attr({
 			disabled: action !== "rotate-by-angle"
@@ -1420,7 +1420,7 @@ function image_flip_and_rotate(){
 
 	$fieldset.find("label").css({display: "block"});
 
-	$w.$Button("Okay", function(){
+	$w.$Button("Okay", () => {
 		var action = $fieldset.find("input[name='flip-or-rotate']:checked").val();
 		var angle_val = $fieldset.find("input[name='rotate-by-angle']:checked").val();
 		if(angle_val === "arbitrary"){
@@ -1432,7 +1432,7 @@ function image_flip_and_rotate(){
 		if(isNaN(angle)){
 			var $msgw = new $FormWindow("Invalid Value").addClass("dialogue-window");
 			$msgw.$main.text("The value specified for Degrees was invalid.");
-			$msgw.$Button("Okay", function(){
+			$msgw.$Button("Okay", () => {
 				$msgw.close();
 			});
 			return;
@@ -1454,7 +1454,7 @@ function image_flip_and_rotate(){
 
 		$w.close();
 	})[0].focus();
-	$w.$Button("Cancel", function(){
+	$w.$Button("Cancel", () => {
 		$w.close();
 	});
 
@@ -1469,7 +1469,7 @@ function image_stretch_and_skew(){
 	var $fieldset_skew = $(E("fieldset")).appendTo($w.$main);
 	$fieldset_skew.append("<legend>Skew</legend><table></table>");
 
-	var $RowInput = function($table, img_src, label_text, default_value, label_unit){
+	var $RowInput = ($table, img_src, label_text, default_value, label_unit) => {
 		var $tr = $(E("tr")).appendTo($table);
 		var $img = $(E("img")).attr({
 			src: "images/transforms/" + img_src + ".png"
@@ -1494,7 +1494,7 @@ function image_stretch_and_skew(){
 	var skew_x = $RowInput($fieldset_skew.find("table"), "skew-x", "Horizontal:", 0, "Degrees");
 	var skew_y = $RowInput($fieldset_skew.find("table"), "skew-y", "Vertical:", 0, "Degrees");
 
-	$w.$Button("Okay", function(){
+	$w.$Button("Okay", () => {
 		var xscale = parseFloat(stretch_x.val())/100;
 		var yscale = parseFloat(stretch_y.val())/100;
 		var hskew = parseFloat(skew_x.val())/360*TAU;
@@ -1504,7 +1504,7 @@ function image_stretch_and_skew(){
 		$w.close();
 	})[0].focus();
 
-	$w.$Button("Cancel", function(){
+	$w.$Button("Cancel", () => {
 		$w.close();
 	});
 
@@ -1519,10 +1519,10 @@ function save_canvas_as(canvas, fileName, savedCallbackUnreliable){
 	}
 
 	// TODO: file name + type dialog
-	canvas.toBlob(function(blob){
-		sanity_check_blob(blob, function(){
+	canvas.toBlob(blob => {
+		sanity_check_blob(blob, () => {
 			var file_saver = saveAs(blob, file_name.replace(/\.(bmp|dib|a?png|gif|jpe?g|jpe|jfif|tiff?|webp|raw)$/, "") + ".png");
-			file_saver.onwriteend = function(){
+			file_saver.onwriteend = () => {
 				// this won't fire in chrome
 				savedCallbackUnreliable();
 			};
@@ -1554,8 +1554,8 @@ function set_as_wallpaper_centered(c){
 		return window.systemSetAsWallpaperCentered(c);
 	}
 
-	c.toBlob(function(blob){
-		sanity_check_blob(blob, function(){
+	c.toBlob(blob => {
+		sanity_check_blob(blob, () => {
 			saveAs(blob, file_name.replace(/\.(bmp|dib|a?png|gif|jpe?g|jpe|jfif|tiff?|webp|raw)$/, "") + " wallpaper.png");
 		});
 	});
@@ -1566,19 +1566,19 @@ function set_as_wallpaper_centered(c){
  * @return {Promise}
  */
 function get_array_buffer_from_canvas(canvas) {
-	return new Promise(function(resolve, reject) {
+	return new Promise((resolve, reject) => {
 		var file_reader = new FileReader();
 
-		file_reader.onloadend = function() {
+		file_reader.onloadend = () => {
 			resolve(file_reader.result);
 		};
 
-		file_reader.onerror = function() {
+		file_reader.onerror = () => {
 			reject(new Error("Failed to read canvas image to array buffer"));
 		};
 
-		canvas.toBlob(function(blob) {
-			sanity_check_blob(blob, function(){
+		canvas.toBlob(blob => {
+			sanity_check_blob(blob, () => {
 				file_reader.readAsArrayBuffer(blob);
 			});
 		});
@@ -1587,8 +1587,8 @@ function get_array_buffer_from_canvas(canvas) {
 
 function save_selection_to_file(){
 	if(selection && selection.canvas){
-		selection.canvas.toBlob(function(blob){
-			sanity_check_blob(blob, function(){
+		selection.canvas.toBlob(blob => {
+			sanity_check_blob(blob, () => {
 				saveAs(blob, "selection.png");
 			});
 		});
@@ -1606,7 +1606,7 @@ function sanity_check_blob(blob, okay_callback){
 			"<a href='https://github.com/1j01/jspaint/issues/118'>Issue #118</a>"
 		);
 		$w.$main.css({maxWidth: "500px"});
-		$w.$Button("OK", function(){
+		$w.$Button("OK", () => {
 			$w.close();
 		});
 		$w.center();
diff --git a/src/help.js b/src/help.js
index 94bfcd6..ee83075 100644
--- a/src/help.js
+++ b/src/help.js
@@ -18,10 +18,10 @@ function show_help(){
 	$iframe.css({backgroundColor: "white"});
 	$help_window.center();
 	
-	var parse_object_params = function($object){
+	var parse_object_params = $object => {
 		// parse an $(<object>) to a plain object of key value pairs
 		var object = {};
-		$object.children("param").each(function(i, param){
+		$object.children("param").each((i, param) => {
 			object[param.name] = param.value;
 		});
 		return object;
@@ -29,13 +29,13 @@ function show_help(){
 	
 	var $last_expanded;
 	
-	var $Item = function(text){
+	var $Item = text => {
 		var $item = $(E("div")).addClass("item").text(text);
-		$item.on("mousedown", function(){
+		$item.on("mousedown", () => {
 			$contents.find(".item").removeClass("selected");
 			$item.addClass("selected");
 		});
-		$item.on("click", function(){
+		$item.on("click", () => {
 			var $li = $item.parent();
 			if($li.is(".folder")){
 				if($last_expanded){
@@ -49,13 +49,13 @@ function show_help(){
 	};
 	
 	var $default_item_li = $(E("li")).addClass("page");
-	$default_item_li.append($Item("Welcome to Help").on("click", function(e){
+	$default_item_li.append($Item("Welcome to Help").on("click", e => {
 		$iframe.attr({src: "help/default.html"});
 	}));
 	$contents.append($default_item_li);
 	
-	$.get("help/mspaint.hhc", function(hhc){
-		$($.parseHTML(hhc)).filter("ul").children().each(function(i, li){
+	$.get("help/mspaint.hhc", hhc => {
+		$($.parseHTML(hhc)).filter("ul").children().each((i, li) => {
 			
 			var object = parse_object_params($(li).children("object"));
 			
@@ -66,10 +66,10 @@ function show_help(){
 			var $folder_items_ul = $(E("ul"));
 			$folder_li.append($folder_items_ul);
 			
-			$(li).children("ul").children().each(function(i, li){
+			$(li).children("ul").children().each((i, li) => {
 				var object = parse_object_params($(li).children("object"));
 				var $item_li = $(E("li")).addClass("page");
-				$item_li.append($Item(object.Name).on("click", function(e){
+				$item_li.append($Item(object.Name).on("click", e => {
 					$iframe.attr({src: "help/" + object.Local});
 				}));
 				$folder_items_ul.append($item_li);
diff --git a/src/helpers.js b/src/helpers.js
index 5951e78..82d5198 100644
--- a/src/helpers.js
+++ b/src/helpers.js
@@ -54,13 +54,13 @@ function Canvas(width, height){
 	
 	new_canvas.ctx = new_ctx;
 	
-	new_ctx.disable_image_smoothing = function(image){
+	new_ctx.disable_image_smoothing = image => {
 		new_ctx.mozImageSmoothingEnabled = false;
 		new_ctx.webkitImageSmoothingEnabled = false;
 		new_ctx.msImageSmoothingEnabled = false;
 		new_ctx.imageSmoothingEnabled = false;
 	};
-	new_ctx.enable_image_smoothing = function(image){
+	new_ctx.enable_image_smoothing = image => {
 		new_ctx.mozImageSmoothingEnabled = true;
 		new_ctx.webkitImageSmoothingEnabled = true;
 		new_ctx.msImageSmoothingEnabled = true;
@@ -71,7 +71,7 @@ function Canvas(width, height){
 	// that reset the image smoothing to disabled
 	// and remove all external calls to disable_image_smoothing
 	
-	new_ctx.copy = function(image){
+	new_ctx.copy = image => {
 		new_canvas.width = image.naturalWidth || image.width;
 		new_canvas.height = image.naturalHeight || image.height;
 		
diff --git a/src/image-manipulation.js b/src/image-manipulation.js
index 5240184..23de321 100644
--- a/src/image-manipulation.js
+++ b/src/image-manipulation.js
@@ -148,11 +148,11 @@ function draw_line_without_pattern_support(ctx, x1, y1, x2, y2, stroke_size){
 	stroke_size = stroke_size || 1;
 	if(aliasing){
 		if(stroke_size > 1){
-			bresenham_line(x1, y1, x2, y2, function(x, y){
+			bresenham_line(x1, y1, x2, y2, (x, y) => {
 				ctx.drawImage(line_brush_canvas, ~~(x - line_brush_canvas.width/2), ~~(y - line_brush_canvas.height/2));
 			});
 		}else{
-			bresenham_line(x1, y1, x2, y2, function(x, y){
+			bresenham_line(x1, y1, x2, y2, (x, y) => {
 				ctx.fillRect(x, y, 1, 1);
 			});
 		}
@@ -368,7 +368,7 @@ function apply_image_transformation(fn){
 	if(selection){
 		selection.replace_source_canvas(new_canvas);
 	}else{
-		undoable(0, function(){
+		undoable(0, () => {
 			this_ones_a_frame_changer();
 			
 			ctx.copy(new_canvas);
@@ -379,7 +379,7 @@ function apply_image_transformation(fn){
 }
 
 function flip_horizontal(){
-	apply_image_transformation(function(original_canvas, original_ctx, new_canvas, new_ctx){
+	apply_image_transformation((original_canvas, original_ctx, new_canvas, new_ctx) => {
 		new_ctx.translate(new_canvas.width, 0);
 		new_ctx.scale(-1, 1);
 		new_ctx.drawImage(original_canvas, 0, 0);
@@ -387,7 +387,7 @@ function flip_horizontal(){
 }
 
 function flip_vertical(){
-	apply_image_transformation(function(original_canvas, original_ctx, new_canvas, new_ctx){
+	apply_image_transformation((original_canvas, original_ctx, new_canvas, new_ctx) => {
 		new_ctx.translate(0, new_canvas.height);
 		new_ctx.scale(1, -1);
 		new_ctx.drawImage(original_canvas, 0, 0);
@@ -395,7 +395,7 @@ function flip_vertical(){
 }
 
 function rotate(angle){
-	apply_image_transformation(function(original_canvas, original_ctx, new_canvas, new_ctx){
+	apply_image_transformation((original_canvas, original_ctx, new_canvas, new_ctx) => {
 		new_ctx.save();
 		switch(angle){
 			case TAU / 4:
@@ -427,7 +427,7 @@ function rotate(angle){
 				var bb_max_x = -Infinity;
 				var bb_min_y = +Infinity;
 				var bb_max_y = -Infinity;
-				var corner = function(x01, y01){
+				var corner = (x01, y01) => {
 					var x = Math.sin(-angle)*h*x01 + Math.cos(+angle)*w*y01;
 					var y = Math.sin(+angle)*w*y01 + Math.cos(-angle)*h*x01;
 					bb_min_x = Math.min(bb_min_x, x);
@@ -466,7 +466,7 @@ function rotate(angle){
 }
 
 function stretch_and_skew(xscale, yscale, hsa, vsa){
-	apply_image_transformation(function(original_canvas, original_ctx, new_canvas, new_ctx){
+	apply_image_transformation((original_canvas, original_ctx, new_canvas, new_ctx) => {
 		var w = original_canvas.width * xscale;
 		var h = original_canvas.height * yscale;
 		
@@ -474,7 +474,7 @@ function stretch_and_skew(xscale, yscale, hsa, vsa){
 		var bb_max_x = -Infinity;
 		var bb_min_y = +Infinity;
 		var bb_max_y = -Infinity;
-		var corner = function(x01, y01){
+		var corner = (x01, y01) => {
 			var x = Math.tan(hsa)*h*x01 + w*y01;
 			var y = Math.tan(vsa)*w*y01 + h*x01;
 			bb_min_x = Math.min(bb_min_x, x);
@@ -568,7 +568,7 @@ function draw_bezier_curve(ctx, start_x, start_y, control_1_x, control_1_y, cont
 	var min_y = Math.min(start_y, control_1_y, control_2_y, end_y);
 	var max_x = Math.max(start_x, control_1_x, control_2_x, end_x);
 	var max_y = Math.max(start_y, control_1_y, control_2_y, end_y);
-	draw_with_swatch(ctx, min_x, min_y, max_x, max_y, stroke_color, function(op_ctx_2d){
+	draw_with_swatch(ctx, min_x, min_y, max_x, max_y, stroke_color, op_ctx_2d => {
 		draw_bezier_curve_without_pattern_support(op_ctx_2d, start_x, start_y, control_1_x, control_1_y, control_2_x, control_2_y, end_x, end_y, stroke_size);
 	});
 }
@@ -577,7 +577,7 @@ function draw_line(ctx, x1, y1, x2, y2, stroke_size){
 	var min_y = Math.min(y1, y2);
 	var max_x = Math.max(x1, x2);
 	var max_y = Math.max(y1, y2);
-	draw_with_swatch(ctx, min_x, min_y, max_x, max_y, stroke_color, function(op_ctx_2d){
+	draw_with_swatch(ctx, min_x, min_y, max_x, max_y, stroke_color, op_ctx_2d => {
 		draw_line_without_pattern_support(op_ctx_2d, x1, y1, x2, y2, stroke_size);
 	});
 	// also works:
@@ -616,7 +616,7 @@ function draw_grid(ctx, scale) {
 	ctx.restore();
 }
 
-(function(){
+(() => {
 
 	var tessy = (function initTesselator() {
 		// function called for each vertex of tesselator output
@@ -792,10 +792,10 @@ function draw_grid(ctx, scale) {
 		}
 	}
 
-	window.draw_line_strip = function(ctx, points){
+	window.draw_line_strip = (ctx, points) => {
 		draw_polygon_or_line_strip(ctx, points, true, false, false);
 	};
-	window.draw_polygon = function(ctx, points, stroke, fill){
+	window.draw_polygon = (ctx, points, stroke, fill) => {
 		draw_polygon_or_line_strip(ctx, points, stroke, fill, true);
 	};
 
@@ -900,7 +900,7 @@ function draw_grid(ctx, scale) {
 		}
 	}
 
-	window.copy_contents_within_polygon = function(canvas, points, x_min, y_min, x_max, y_max){
+	window.copy_contents_within_polygon = (canvas, points, x_min, y_min, x_max, y_max) => {
 		// Copy the contents of the given canvas within the polygon given by points bounded by x/y_min/max
 		x_max = Math.max(x_max, x_min + 1);
 		y_max = Math.max(y_max, y_min + 1);
@@ -923,7 +923,7 @@ function draw_grid(ctx, scale) {
 	}
 
 	// TODO: maybe shouldn't be external...
-	window.draw_with_swatch = function(ctx, x_min, y_min, x_max, y_max, swatch, callback) {
+	window.draw_with_swatch = (ctx, x_min, y_min, x_max, y_max, swatch, callback) => {
 		var stroke_margin = ~~(stroke_size * 1.1);
 		
 		x_max = Math.max(x_max, x_min + 1);
diff --git a/src/imgur.js b/src/imgur.js
index a241dcb..823fd69 100644
--- a/src/imgur.js
+++ b/src/imgur.js
@@ -22,12 +22,12 @@ function show_imgur_uploader(blob){
 		overflow: "auto",
 		marginBottom: "0.5em",
 	});
-	$preview_image.on("load", function(){
+	$preview_image.on("load", () => {
 		$imgur_window.css({width: "auto"});
 		$imgur_window.center();
 	});
 
-	var $upload_button = $imgur_window.$Button("Upload", function(){
+	var $upload_button = $imgur_window.$Button("Upload", () => {
 
 		$preview_image_area.remove();
 		$upload_button.remove();
@@ -43,7 +43,7 @@ function show_imgur_uploader(blob){
 			textAlign: "center",
 		});
 
-		var parseImgurResponseJSON = function(responseJSON){
+		var parseImgurResponseJSON = responseJSON => {
 			try {
 				var response = JSON.parse(responseJSON);
 			} catch(error) {
@@ -86,7 +86,7 @@ function show_imgur_uploader(blob){
 		var req = new XMLHttpRequest();
 
 		if(req.upload){
-			req.upload.addEventListener('progress', function(event){
+			req.upload.addEventListener('progress', event => {
 				if(event.lengthComputable){
 					var progress_value = event.loaded / event.total;
 					var percentage_text = Math.floor(progress_value * 100) + "%";
@@ -96,7 +96,7 @@ function show_imgur_uploader(blob){
 			}, false);
 		}
 
-		req.addEventListener("readystatechange", function() { 
+		req.addEventListener("readystatechange", () => { 
 			if(req.readyState == 4 && req.status == 200){
 				$progress.add($progress_percent).remove();
 
@@ -121,10 +121,10 @@ function show_imgur_uploader(blob){
 				// TODO: a button to copy the URL to the clipboard
 				// (also maybe put the URL in a readonly input)
 				
-				var $delete_button = $imgur_window.$Button("Delete", function(){
+				var $delete_button = $imgur_window.$Button("Delete", () => {
 					var req = new XMLHttpRequest();
 
-					req.addEventListener("readystatechange", function() { 
+					req.addEventListener("readystatechange", () => { 
 						if(req.readyState == 4 && req.status == 200){
 							$delete_button.remove();
 
@@ -150,7 +150,7 @@ function show_imgur_uploader(blob){
 
 					$imgur_status.text("Deleting...");
 				});
-				var $okay_button = $imgur_window.$Button("OK", function(){
+				var $okay_button = $imgur_window.$Button("OK", () => {
 					$imgur_window.close();
 				});
 			}else if(req.readyState == 4){
@@ -170,7 +170,7 @@ function show_imgur_uploader(blob){
 
 		$imgur_status.text("Uploading...");
 	});
-	var $cancel_button = $imgur_window.$Button("Cancel", function(){
+	var $cancel_button = $imgur_window.$Button("Cancel", () => {
 		$imgur_window.close();
 	});
 	$imgur_window.width(300);
diff --git a/src/manage-storage.js b/src/manage-storage.js
index 55c5a5d..ef09af6 100644
--- a/src/manage-storage.js
+++ b/src/manage-storage.js
@@ -20,12 +20,12 @@ function storage_quota_exceeded(){
 		"<p>You can still save the current image with <b>File > Save</b>. " +
 		"You should save frequently, or free up enough space to keep the image safe.</p>"
 	);
-	$w.$Button("View and manage storage", function(){
+	$w.$Button("View and manage storage", () => {
 		$w.close();
 		ignoring_quota_exceeded = false;
 		manage_storage();
 	});
-	$w.$Button("Ignore", function(){
+	$w.$Button("Ignore", () => {
 		$w.close();
 		ignoring_quota_exceeded = true;
 	});
@@ -44,11 +44,11 @@ function manage_storage(){
 	var $message = $(E("p")).appendTo($storage_manager.$main).html(
 		"Any images you've saved to your computer with <b>File > Save</b> will not be affected."
 	);
-	$storage_manager.$Button("Close", function(){
+	$storage_manager.$Button("Close", () => {
 		$storage_manager.close();
 	});
 	
-	var addRow = function(k, imgSrc){
+	var addRow = (k, imgSrc) => {
 		var $tr = $(E("tr")).appendTo($table);
 		
 		var $img = $(E("img")).attr({src: imgSrc});
@@ -61,7 +61,7 @@ function manage_storage(){
 		$(E("td")).append($open_link).appendTo($tr);
 		$(E("td")).append($remove).appendTo($tr);
 		
-		$remove.on("click", function(){
+		$remove.on("click", () => {
 			localStorage.removeItem(k);
 			$tr.remove();
 			if($table.find("tr").length == 0){
diff --git a/src/sessions.js b/src/sessions.js
index a54bc8e..e330ad8 100644
--- a/src/sessions.js
+++ b/src/sessions.js
@@ -1,5 +1,5 @@
 
-(function(){
+(() => {
 
 	var log = function(){
 		if(typeof console !== "undefined"){
@@ -100,12 +100,12 @@
 			var lsid = "image#" + session_id;
 			log("local storage id: " + lsid);
 			// save image to storage
-			var save_image_to_storage = function () {
+			var save_image_to_storage = () => {
 				var save_paused = handle_data_loss();
 				if (save_paused) {
 					return;
 				}
-				storage.set(lsid, canvas.toDataURL("image/png"), function (err) {
+				storage.set(lsid, canvas.toDataURL("image/png"), err => {
 					if (err) {
 						if (err.quotaExceeded) {
 							storage_quota_exceeded();
@@ -118,7 +118,7 @@
 					}
 				});
 			};
-			storage.get(lsid, function (err, uri) {
+			storage.get(lsid, (err, uri) => {
 				if (err) {
 					if (localStorageAvailable) {
 						show_error_message("Failed to retrieve image from local storage:", err);
@@ -129,7 +129,7 @@
 					}
 				}
 				else if (uri) {
-					open_from_URI(uri, function (err) {
+					open_from_URI(uri, err => {
 						if (err) {
 							return show_error_message("Failed to open image from local storage:", err);
 						}
@@ -196,14 +196,14 @@
 			session.id = session_id;
 			file_name = "[Loading " + session.id + "]";
 			update_title();
-			var on_firebase_loaded = function () {
+			var on_firebase_loaded = () => {
 				file_name = "[" + session.id + "]";
 				update_title();
 				session.start();
 			};
 			if (!FireSession.fb_root) {
 				$.getScript("lib/firebase.js")
-					.done(function () {
+					.done(() => {
 						var config = {
 							apiKey: "AIzaSyBgau8Vu9ZE8u_j0rp-Lc044gYTX5O3X9k",
 							authDomain: "jspaint.firebaseapp.com",
@@ -216,7 +216,7 @@
 						FireSession.fb_root = firebase.database().ref("/");
 						on_firebase_loaded();
 					})
-					.fail(function () {
+					.fail(() => {
 						show_error_message("Failed to load Firebase; the document will not load, and changes will not be saved.");
 						file_name = "[Failed to load " + session.id + "]";
 						update_title();
@@ -239,14 +239,14 @@
 				// "<a href='https://github.com/1j01/jspaint/issues/68'>this issue</a> to show interest, and/or subscribe for updates.</p>"
 			);
 			$w.$main.css({ maxWidth: "500px" });
-			$w.$Button("OK", function () {
+			$w.$Button("OK", () => {
 				$w.close();
 			});
 			$w.center();
 			// Wrap the Firebase API because they don't
 			// provide a great way to clean up event listeners
 			session._fb_listeners = [];
-			var _fb_on = function (fb, event_type, callback, error_callback) {
+			var _fb_on = (fb, event_type, callback, error_callback) => {
 				session._fb_listeners.push({ fb, event_type, callback, error_callback });
 				fb.on(event_type, callback, error_callback);
 			};
@@ -267,7 +267,7 @@
 			session.fb_user.set(user);
 			// @TODO: Execute the above two lines when .info/connected
 			// For each existing and new user
-			_fb_on(session.fb_users, "child_added", function (snap) {
+			_fb_on(session.fb_users, "child_added", snap => {
 				// Is this you?
 				if (snap.key === user_id) {
 					// You already have a cursor.
@@ -294,7 +294,7 @@
 					transition: "opacity 0.5s",
 				});
 				// When the cursor data changes
-				_fb_on(fb_other_user, "value", function (snap) {
+				_fb_on(fb_other_user, "value", snap => {
 					other_user = snap.val();
 					// If the user has left
 					if (other_user == null) {
@@ -303,7 +303,7 @@
 					}
 					else {
 						// Draw the cursor
-						var draw_cursor = function () {
+						var draw_cursor = () => {
 							cursor_canvas.width = cursor_image.width;
 							cursor_canvas.height = cursor_image.height;
 							var cctx = cursor_canvas.ctx;
@@ -334,7 +334,7 @@
 			});
 			var previous_uri;
 			var pointer_operations = [];
-			var sync = function () {
+			var sync = () => {
 				var save_paused = handle_data_loss();
 				if (save_paused) {
 					return;
@@ -354,7 +354,7 @@
 			};
 			$canvas.on("change.session-hook", sync);
 			// Any time we change or recieve the image data
-			_fb_on(session.fb_data, "value", function (snap) {
+			_fb_on(session.fb_data, "value", snap => {
 				log("data update");
 				var uri = snap.val();
 				if (uri == null) {
@@ -367,7 +367,7 @@
 					saved = true; // hopefully
 					// Load the new image data
 					var img = new Image();
-					img.onload = function () {
+					img.onload = () => {
 						// Cancel any in-progress pointer operations
 						if (pointer_operations.length) {
 							$G.triggerHandler("pointerup", "cancel");
@@ -389,13 +389,13 @@
 					};
 					img.src = uri;
 				}
-			}, function (error) {
+			}, error => {
 				show_error_message("Failed to retrieve data from Firebase. The document will not load, and changes will not be saved.", error);
 				file_name = "[Failed to load " + session.id + "]";
 				update_title();
 			});
 			// Update the cursor status
-			$G.on("pointermove.session-hook", function (e) {
+			$G.on("pointermove.session-hook", e => {
 				var m = e2c(e);
 				session.fb_user.child("cursor").update({
 					x: m.x,
@@ -403,7 +403,7 @@
 					away: false,
 				});
 			});
-			$G.on("blur.session-hook", function (e) {
+			$G.on("blur.session-hook", e => {
 				session.fb_user.child("cursor").update({
 					away: true,
 				});
@@ -438,17 +438,17 @@
 	// Handle the starting, switching, and ending of sessions from the location.hash
 
 	var current_session;
-	var end_current_session = function(){
+	var end_current_session = () => {
 		if(current_session){
 			log("ending current session");
 			current_session.end();
 			current_session = null;
 		}
 	};
-	var generate_session_id = function(){
+	var generate_session_id = () => {
 		return (Math.random()*Math.pow(2, 32)).toString(16).replace(".", "");
 	};
-	var update_session_from_location_hash = function(e){
+	var update_session_from_location_hash = e => {
 		// TODO: should #load: be separate from #session:/#local:,
 		// and be able to load *into* a session, rather than just start one?
 		// well I guess loading into a session wouldn't be that helpful if it makes a new image anyways
@@ -494,18 +494,18 @@
 			end_current_session();
 
 			// TODO: fix loading duplicately, from popstate and hashchange
-			open_from_URI(url, function(err){
+			open_from_URI(url, err => {
 				if(err){
 					show_resource_load_error_message();
 				}
 				// TODO: saved = false;?
 				// NOTE: the following is intended to run regardless of error (as opposed to returning if there's an error)
 				// FIXME: race condition (make the timeout long and try to fix it with a flag or something )
-				setTimeout(function(){
+				setTimeout(() => {
 					// NOTE: this "change" event doesn't *guarantee* there was a change :/
 					// let alone that there was a user interaction with the currently loaded document
 					// that is, it also triggers for session changes, which I'm trying to avoid here
-					$canvas.one("change", function(){
+					$canvas.one("change", () => {
 						if(location.hash === hash_loading_url_from){
 							log("switching to new session from #load: URL because of user interaction");
 							end_current_session();
@@ -526,7 +526,7 @@
 		}
 	};
 
-	$G.on("hashchange popstate", function(e){
+	$G.on("hashchange popstate", e => {
 		log(e.type, location.hash);
 		update_session_from_location_hash();
 	});
diff --git a/src/storage.js b/src/storage.js
index 4dd8f8b..4eb3c54 100644
--- a/src/storage.js
+++ b/src/storage.js
@@ -1,10 +1,10 @@
 // TODO: remove "ref" cruft from being compiled from CoffeeScript
 // or maybe replace this module with localforage actually
 
-(function() {
+((() => {
   var isArray, localStore, ref, ref1;
 
-  isArray = (ref = Array.isArray) != null ? ref : function(a) {
+  isArray = (ref = Array.isArray) != null ? ref : a => {
     return ("" + a) !== a && {}.toString.call(a) === "[object Array]";
   };
 
@@ -79,4 +79,4 @@
 
   window.storage = localStore;
 
-}).call(this);
+})).call(this);
diff --git a/src/theme.js b/src/theme.js
index 8da6e60..88f883a 100644
--- a/src/theme.js
+++ b/src/theme.js
@@ -1,7 +1,7 @@
-(function() {
+(() => {
 	var default_theme = "classic.css";
 	var theme_storage_key = "jspaint theme";
-	var href_for = function(theme) {
+	var href_for = theme => {
 		return "styles/themes/" + theme;
 	};
 	
@@ -15,7 +15,7 @@
 	var iid;
 	function wait_for_theme_loaded(theme, callback) {
 		clearInterval(iid);
-		iid = setInterval(function() {
+		iid = setInterval(() => {
 			var theme_loaded =
 				getComputedStyle(document.documentElement)
 					.getPropertyValue("--theme-loaded")
@@ -34,11 +34,11 @@
 	theme_link.id = "theme-link";
 	document.head.appendChild(theme_link);
 
-	window.get_theme = function() {
+	window.get_theme = () => {
 		return current_theme;
 	};
 
-	window.set_theme = function(theme) {
+	window.set_theme = theme => {
 		current_theme = theme;
 
 		try {
@@ -51,7 +51,7 @@
 			$(window).trigger("resize"); // not exactly, but get dynamic cursor to update its offset
 		});
 
-		wait_for_theme_loaded(theme, function(){
+		wait_for_theme_loaded(theme, () => {
 			$(window).triggerHandler("theme-load");
 		});
 		theme_link.href = href_for(theme);
diff --git a/src/tool-options.js b/src/tool-options.js
index cabd227..0b3663d 100644
--- a/src/tool-options.js
+++ b/src/tool-options.js
@@ -9,19 +9,27 @@ var pencil_size = 1;
 var stroke_size = 1; // lines, curves, shape outlines
 var tool_transparent_mode = false;
 
-var ChooserCanvas = function(
-	url, invert,
-	width, height,
-	sourceX, sourceY, sourceWidth, sourceHeight,
-	destX, destY, destWidth, destHeight
-){
+var ChooserCanvas = (
+    url,
+    invert,
+    width,
+    height,
+    sourceX,
+    sourceY,
+    sourceWidth,
+    sourceHeight,
+    destX,
+    destY,
+    destWidth,
+    destHeight
+) => {
 	var c = new Canvas(width, height);
 	var img = ChooserCanvas.cache[url];
 	if(!img){
 		img = ChooserCanvas.cache[url] = E("img");
 		img.src = url;
 	}
-	var render = function(){
+	var render = () => {
 		c.ctx.drawImage(
 			img,
 			sourceX, sourceY, sourceWidth, sourceHeight,
@@ -43,22 +51,22 @@ var ChooserCanvas = function(
 };
 ChooserCanvas.cache = {};
 
-var $Choose = function(things, display, choose, is_chosen){
+var $Choose = (things, display, choose, is_chosen) => {
 	var $chooser = $(E("div")).addClass("chooser");
-	$chooser.on("update", function(){
+	$chooser.on("update", () => {
 		$chooser.empty();
 		for(var i=0; i<things.length; i++){
-			(function(thing){
+			(thing => {
 				var $option_container = $(E("div")).appendTo($chooser);
 				var $option = $();
-				var choose_thing = function(){
+				var choose_thing = () => {
 					if(is_chosen(thing)){
 						return; // unnecessary optimization
 					}
 					choose(thing);
 					$G.trigger("option-changed");
 				}
-				var update = function(){
+				var update = () => {
 					var selected_color = get_theme() === "modern.css" ? "#0178d7" : "#000080"; // TODO: get from a CSS variable
 					$option_container.css({
 						backgroundColor: is_chosen(thing) ? selected_color : ""
@@ -72,10 +80,10 @@ var $Choose = function(things, display, choose, is_chosen){
 				$G.on("option-changed", update);
 				
 				$option_container.on("pointerdown click", choose_thing);
-				$chooser.on("pointerdown", function(){
+				$chooser.on("pointerdown", () => {
 					$option_container.on("pointerenter", choose_thing);
 				});
-				$G.on("pointerup", function(){
+				$G.on("pointerup", () => {
 					$option_container.off("pointerenter", choose_thing);
 				});
 				
@@ -84,14 +92,14 @@ var $Choose = function(things, display, choose, is_chosen){
 	});
 	return $chooser;
 };
-var $ChooseShapeStyle = function(){
+var $ChooseShapeStyle = () => {
 	var $chooser = $Choose(
 		[
 			{stroke: true, fill: false},
 			{stroke: true, fill: true},
 			{stroke: false, fill: true}
 		],
-		function(a, is_chosen){
+		(a, is_chosen) => {
 			var sscanvas = new Canvas(39, 21);
 			var ssctx = sscanvas.ctx;
 			
@@ -117,11 +125,11 @@ var $ChooseShapeStyle = function(){
 			
 			return sscanvas;
 		},
-		function(a){
+		a => {
 			$chooser.stroke = a.stroke;
 			$chooser.fill = a.fill;
 		},
-		function(a){
+		a => {
 			return $chooser.stroke === a.stroke && $chooser.fill === a.fill;
 		}
 	).addClass("choose-shape-style");
@@ -132,49 +140,44 @@ var $ChooseShapeStyle = function(){
 	return $chooser;
 };
 
-var $choose_brush = $Choose(
-	(function(){
-		var brush_shapes = ["circle", "square", "reverse_diagonal", "diagonal"];
-		var circular_brush_sizes = [7, 4, 1];
-		var brush_sizes = [8, 5, 2];
-		var things = [];
-		brush_shapes.forEach((brush_shape)=> {
-			var sizes = brush_shape === "circle" ? circular_brush_sizes : brush_sizes;
-			sizes.forEach((brush_size)=> {
-				things.push({
-					shape: brush_shape,
-					size: brush_size,
-				});
-			});
-		});
-		return things;
-	})(),
-	function(o, is_chosen){
-		var cbcanvas = new Canvas(10, 10);
-		
-		var shape = o.shape;
-		var size = o.size;
-		
-		cbcanvas.ctx.fillStyle =
-		cbcanvas.ctx.strokeStyle =
-			is_chosen ? "#fff" : "#000";
-		
-		render_brush(cbcanvas.ctx, shape, size);
-		
-		return cbcanvas;
-	},
-	function(o){
-		brush_shape = o.shape;
-		brush_size = o.size;
-	},
-	function(o){
-		return brush_shape === o.shape && brush_size === o.size;
-	}
-).addClass("choose-brush");
+var $choose_brush = $Choose((() => {
+    var brush_shapes = ["circle", "square", "reverse_diagonal", "diagonal"];
+    var circular_brush_sizes = [7, 4, 1];
+    var brush_sizes = [8, 5, 2];
+    var things = [];
+    brush_shapes.forEach((brush_shape)=> {
+        var sizes = brush_shape === "circle" ? circular_brush_sizes : brush_sizes;
+        sizes.forEach((brush_size)=> {
+            things.push({
+                shape: brush_shape,
+                size: brush_size,
+            });
+        });
+    });
+    return things;
+})(), (o, is_chosen) => {
+    var cbcanvas = new Canvas(10, 10);
+    
+    var shape = o.shape;
+    var size = o.size;
+    
+    cbcanvas.ctx.fillStyle =
+    cbcanvas.ctx.strokeStyle =
+        is_chosen ? "#fff" : "#000";
+    
+    render_brush(cbcanvas.ctx, shape, size);
+    
+    return cbcanvas;
+}, o => {
+    brush_shape = o.shape;
+    brush_size = o.size;
+}, o => {
+    return brush_shape === o.shape && brush_size === o.size;
+}).addClass("choose-brush");
 
 var $choose_eraser_size = $Choose(
 	[4, 6, 8, 10],
-	function(size, is_chosen){
+	(size, is_chosen) => {
 		var cecanvas = new Canvas(39, 16);
 		
 		cecanvas.ctx.fillStyle = is_chosen ? "#fff" : "#000";
@@ -182,17 +185,17 @@ var $choose_eraser_size = $Choose(
 		
 		return cecanvas;
 	},
-	function(size){
+	size => {
 		eraser_size = size;
 	},
-	function(size){
+	size => {
 		return eraser_size === size;
 	}
 ).addClass("choose-eraser");
 
 var $choose_stroke_size = $Choose(
 	[1, 2, 3, 4, 5],
-	function(size, is_chosen){
+	(size, is_chosen) => {
 		var w = 39, h = 12, b = 5;
 		var cscanvas = new Canvas(w, h);
 		var center_y = (h - size) / 2;
@@ -200,10 +203,10 @@ var $choose_stroke_size = $Choose(
 		cscanvas.ctx.fillRect(b, ~~center_y, w - b*2, size);
 		return cscanvas;
 	},
-	function(size){
+	size => {
 		stroke_size = size;
 	},
-	function(size){
+	size => {
 		return stroke_size === size;
 	}
 ).addClass("choose-stroke-size");
@@ -211,7 +214,7 @@ var $choose_stroke_size = $Choose(
 var magnifications = [1, 2, 6, 8, 10];
 var $choose_magnification = $Choose(
 	magnifications,
-	function(scale, is_chosen){
+	(scale, is_chosen) => {
 		var i = magnifications.indexOf(scale);
 		var secret = scale === 10; // 10x is secret
 		var chooser_canvas = ChooserCanvas(
@@ -226,16 +229,16 @@ var $choose_magnification = $Choose(
 		}
 		return chooser_canvas;
 	},
-	function(scale){
+	scale => {
 		set_magnification(scale);
 	},
-	function(scale){
+	scale => {
 		return scale === magnification;
 	}
 ).addClass("choose-magnification")
 .css({position: "relative"}); // positioning context for above `position: "absolute"` canvas
 
-$choose_magnification.on("update", function(){
+$choose_magnification.on("update", () => {
 	$choose_magnification
 		.find(".secret-option")
 		.parent()
@@ -245,7 +248,7 @@ $choose_magnification.on("update", function(){
 var airbrush_sizes = [9, 16, 24];
 var $choose_airbrush_size = $Choose(
 	airbrush_sizes,
-	function(size, is_chosen){
+	(size, is_chosen) => {
 		
 		var image_width = 72; // width of source image
 		var i = airbrush_sizes.indexOf(size); // 0 or 1 or 2
@@ -265,17 +268,17 @@ var $choose_airbrush_size = $Choose(
 			0, 0, w, h // x, y, width, height on created destination canvas
 		);
 	},
-	function(size){
+	size => {
 		airbrush_size = size;
 	},
-	function(size){
+	size => {
 		return size === airbrush_size;
 	}
 ).addClass("choose-airbrush-size");
 
 var $choose_transparent_mode = $Choose(
 	[false, true],
-	function(_tool_transparent_mode, is_chosen){
+	(_tool_transparent_mode, is_chosen) => {
 		var sw = 35, sh = 23; // width, height from source image
 		var b = 2; // margin by which the source image is inset on the destination
 		var theme_folder = `images/${get_theme().replace(/\.css/, "")}`;
@@ -287,10 +290,10 @@ var $choose_transparent_mode = $Choose(
 			b, b, sw, sh // x, y, width, height on created destination canvas
 		);
 	},
-	function(_tool_transparent_mode){
+	_tool_transparent_mode => {
 		tool_transparent_mode = _tool_transparent_mode;
 	},
-	function(_tool_transparent_mode){
+	_tool_transparent_mode => {
 		return _tool_transparent_mode === tool_transparent_mode;
 	}
 ).addClass("choose-transparent-mode");
diff --git a/src/tools.js b/src/tools.js
index 24283f4..60d91c3 100644
--- a/src/tools.js
+++ b/src/tools.js
@@ -33,7 +33,7 @@ tools = [{
 		// The inverty brush is continuous in space which means
 		// paint(ctx, x, y) will be called for each pixel the pointer moves
 		// and we only need to record individual pointer events to make the polygon
-		var onpointermove = function(e){
+		var onpointermove = e => {
 			var pointer = e2c(e);
 			// Constrain the pointer to the canvas
 			pointer.x = Math.min(canvas.width, pointer.x);
@@ -49,7 +49,7 @@ tools = [{
 			tool.y_max = Math.max(pointer.y, tool.y_max);
 		};
 		$G.on("pointermove", onpointermove);
-		$G.one("pointerup", function(){
+		$G.one("pointerup", () => {
 			$G.off("pointermove", onpointermove);
 		});
 	},
@@ -144,10 +144,10 @@ tools = [{
 			selection = null;
 		}
 		var pointer_has_moved = false;
-		$G.one("pointermove", function(){
+		$G.one("pointermove", () => {
 			pointer_has_moved = true;
 		});
-		$G.one("pointerup", function(){
+		$G.one("pointerup", () => {
 			if(!pointer_has_moved && selection){
 				selection.draw();//?
 				selection.destroy();
@@ -301,7 +301,7 @@ tools = [{
 	},
 	pointerdown: function(){
 		var _this = this;
-		$G.one("pointerup", function(){
+		$G.one("pointerup", () => {
 			_this.$options.css({
 				background: ""
 			});
@@ -535,10 +535,10 @@ tools = [{
 			textbox.destroy();
 		}
 		var pointer_has_moved = false;
-		$G.one("pointermove", function(){
+		$G.one("pointermove", () => {
 			pointer_has_moved = true;
 		});
-		$G.one("pointerup", function(){
+		$G.one("pointerup", () => {
 			if(!pointer_has_moved && textbox){
 				textbox.draw();
 				textbox.destroy();
@@ -716,7 +716,7 @@ tools = [{
 			// @TODO: stop needing this:
 			tool.canvas_base = canvas;
 			
-			undoable(function(){
+			undoable(() => {
 				// @TODO: stop needing this:
 				tool.canvas_base = undos[undos.length-1];
 				
diff --git a/src/vaporwave-fun.js b/src/vaporwave-fun.js
index 39d7008..9229357 100644
--- a/src/vaporwave-fun.js
+++ b/src/vaporwave-fun.js
@@ -1,4 +1,4 @@
-(function () {
+(() => {
 	var rAF_ID, rotologo, $window, space_phase_key_handler, player, player_placeholder;
 	var vaporwave_active = false;
 
@@ -8,7 +8,7 @@
 		$window = $();
 	}
 
-	var wait_for_youtube_api = function (callback) {
+	var wait_for_youtube_api = callback => {
 		if (typeof YT !== "undefined") {
 			callback();
 		} else {
@@ -18,13 +18,13 @@
 			firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
 
 			// The YouTube API will call this global function when loaded and ready.
-			window.onYouTubeIframeAPIReady = function () {
+			window.onYouTubeIframeAPIReady = () => {
 				callback();
 			};
 		}
 	};
 
-	var stop_vaporwave = function () {
+	var stop_vaporwave = () => {
 		vaporwave_active = false;
 
 		cancelAnimationFrame(rAF_ID);
@@ -43,7 +43,7 @@
 		// bepis pepsi isded pepsi isded
 	};
 
-	var start_vaporwave = function () {
+	var start_vaporwave = () => {
 		vaporwave_active = true;
 
 		rotologo = document.createElement("img");
@@ -66,7 +66,7 @@
 			opacity: "0",
 		});
 
-		var animate = function () {
+		var animate = () => {
 			rAF_ID = requestAnimationFrame(animate);
 
 			$(rotologo).css({
@@ -123,7 +123,7 @@
 		// NOTE: placeholder not a container; the YT API replaces the element passed in the DOM
 		// but keeps inline styles apparently, and maybe other things, I don't know; it's weird
 
-		wait_for_youtube_api(function () {
+		wait_for_youtube_api(() => {
 			player = new YT.Player(player_placeholder, {
 				height: "390",
 				width: "640",
@@ -155,7 +155,7 @@
 		function onPlayerStateChange(event) {
 			if (event.data == YT.PlayerState.PLAYING) {
 				// TODO: pause and resume this timer with the video
-				setTimeout(function(){
+				setTimeout(() => {
 					$(rotologo).css({opacity: 1});
 				}, 14150);
 			}
@@ -174,7 +174,7 @@
 		}
 
 		var is_theoretically_playing = true;
-		space_phase_key_handler = function (e) {
+		space_phase_key_handler = e => {
 			// press space to phase in and out of space phase スペース相 - windows 98 マイクロソフト 『ＷＩＮＴＲＡＰ』 X 将来のオペレーティングシステムサウンド 1998 VAPORWAVE
 			if (e.which === 32) {
 				// TODO: record player SFX
@@ -198,7 +198,7 @@
 		addEventListener("keydown", space_phase_key_handler);
 	};
 
-	var toggle_vaporwave = function () {
+	var toggle_vaporwave = () => {
 		if (vaporwave_active) {
 			stop_vaporwave();
 		} else {
@@ -208,4 +208,4 @@
 
 	addEventListener("keydown", Konami.code(toggle_vaporwave));
 
-}());
+})();