FYTE /Fast YouTube Embedded/ PlayerJS
Hugely improves load speed of pages with lots of embedded Youtube videos by instantly showing clickable and immediately accessible placeholders, then the thumbnails are loaded in background. Optionally a fast simple HTML5 direct playback (720p max) can be selected if available for the video.
Add YouTube Video ProgressJS
Adds a progress bars (or dots) at bottom of video, a progress text which includes video quality and subtitle indicators, and a chapter title box on the YouTube video page.
Video Background Play FixJS
Prevents YouTube and Vimeo from pausing videos when minimizing or switching tabs. Cross-browser port of https://addons.mozilla.org/en-US/firefox/addon/video-background-play-fix/
Related Links PagerJS
Navigate sideways! When you click a link, related links on the current page are carried with you. They can be accessed from a pager on the target page, so you won't have to go back in your browser.
Table of Contents EverywhereJS
On pages which do not have a Table of Contents, but should do, create one! (I actually use this as a bookmarklet, so I can load it onto the current page only when I want it.)
URLs Need TitlesJS
When you paste a URL to a friend, it is useful if it contains the title of the page. This script adds these missing titles for common websites using # part of URL. In other words, it turns non-semantic URLs into semantic URLs!