Soashable

Soashable is an Open Source (on SourceForge) web-based, multi-protocol instant messaging client written in pure Javascript.

Besides the hosted Web app that supports three major IM clients, you can take Soashable and integrate it into your personal site by installing it on your server. The chat windows are currently full of all sorts of debugging gobbledy-goop, but I successfully had conversations with people on AIM and Yahoo without a hitch.

Homepage

Download from Sourceforge.net

Source:Mashable!