EchoWaves - Opensource Social Group Chat written in Ruby On Rails
Unsee - The ability to open a chat session and message then delete it from history forever just like tlk.
Shtuff Chat - Free Group / Team chat with persistent history.
Meet in Chat - Meet new people. Have fun sharing photos.
Anologue - Disposable online chat.
nohistory.chat - nohistory.chat - free, anonymous and disposable web chat.