Anologue - Disposable online chat.
EchoWaves - Opensource Social Group Chat written in Ruby On Rails
JabbR - A chat application built with ASP.NET and SignalR.
Chatango - Add free live chat to any web page. Chatango is a live group on your site
Kandan - Open Source private chat server. Your own private Chat server in minutes, plus additional features.
Meet in Chat - Meet new people. Have fun sharing photos.