The basic concept is that users register channels where connected viewers can watch videos from different video hosts (e.g., YouTube, Twitch) and the playback is synchronized for all the viewers in the channel.
Each channel has a playlist where users can queue up videos to play, as well as an integrated chatroom for discussion.
The official server is located at https://cytu.be
, but there are other public servers hosted for various communities.
Built using node.js, requires MySQL as its back-end.