aims to be a secure IM for multiple platforms. Keep in touch is an attempt to create a secure instant messenger - it supports its own XML based protocol aswell as ICQ and AIM
allows you to create a chat community and talk to people who are currently reading the same web page as you are. Just add gabbly.com/ before the site's url. For example gabbly.com/cnn.com (IE not supported)
brings IM (instant messaging) to IRC clients. For people who have an IRC client running all the time and don't want to run an additional MSN/AIM/whatever client. Currently supports XMPP/Jabber (including Google Talk), MSN Messenger, Yahoo! Messenger, AIM and ICQ.