PUBLIC MARKS with tags jabber & "open source"

Instantbird is a multi-protocol Instant Messaging client. Using it, you can connect to all your different IM accounts. It uses the Mozilla rendering engine to display IMs, and the Pidgin libpurple to connect to the different networks. Instantbird is a free and open source software. So you are free to use, distribute and modify it.

JWChat is a full featured, web-based Jabber™ client. Written using AJAX technology it relies on JavaScript and HTML at the client-side only. It supports basic jabber instant messaging, roster management and groupchats based on the MUC protocol.