Youtube-Sync is a project that aims to sync up video streams to allow students at the University of Illinois to view prerecorded lectures together in real time. This project uses the Video.js API.
As of now, the video player can support up to 4 people watching at the same time. Any user can pause/play the video or skip ahead/behind and these changes will be synchronized between all users.
Future features include websockets functionality to reduce server load and a built-in chat.
Visit the wiki page for further documentation of the project.