Found this when looking for an internal corporate chat system that can authenticate with LDAP.. implementing now.. very cool app though anyone heard of it... you can also manage multiple servers with it thru XMPP:
Looks very cool! Will report how the webchat client works with the chat server after/if I get ldap auth working (having a bit of trouble with that but will get it... darn dn setting heh)
http://www.getvines.org/
https://github.com/negativecode/vines