todo.tmLanguage

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>fileTypes</key>
	<array>
		<string>todo</string>
	</array>
	<key>name</key>
	<string>TODO</string>
	<key>patterns</key>
	<array>
		<dict>
			<key>comment</key>
			<string>comment</string>
			<key>match</key>
			<string>\s+(//).*$\n?</string>
			<key>name</key>
			<string>comment.line.double-slash.todo</string>
		</dict>
		<dict>
			<key>comment</key>
			<string>urgent tasks</string>
			<key>match</key>
			<string>^\s*(TODO!|WAIT)</string>
			<key>name</key>
			<string>keyword.other.todo</string>
		</dict>
		<dict>
			<key>comment</key>
			<string>normal tasks</string>
			<key>match</key>
			<string>^\s*TODO</string>
			<key>name</key>
			<string>storage.type.todo</string>
		</dict>
		<dict>
			<key>comment</key>
			<string>completed tasks</string>
			<key>match</key>
			<string>^\s*(DONE|SKIP)</string>
			<key>name</key>
			<string>markup.italic</string>
		</dict>
		<dict>
			<key>captures</key>
			<dict>
				<key>1</key>
				<dict>
					<key>name</key>
					<string>constant.numeric.todo</string>
				</dict>
				<key>3</key>
				<dict>
					<key>name</key>
					<string>keyword.control.todo</string>
				</dict>
			</dict>
			<key>comment</key>
			<string>tag</string>
			<key>match</key>
			<string>\[(\d\d:\d\d)?(, )?\S*\] (\S*:)</string>
			<key>name</key>
			<string>string.quoted.todo</string>
		</dict>
		<dict>
			<key>comment</key>
			<string>reference</string>
			<key>match</key>
			<string>&lt;.*&gt;</string>
			<key>name</key>
			<string>string.quoted.todo</string>
		</dict>
	</array>
	<key>scopeName</key>
	<string>text.todo</string>
	<key>uuid</key>
	<string>eb027985-507d-43c6-bdfa-9d49f807aeec</string>
</dict>
</plist>

Sublime 3 TODO highlighting. Download to Packages/User.