Jabber

JabberIM is a full-featured consumer and business instant messaging client for Windows. JabberIM is one of several Windows clients that are compatible with the Jabber technology. Features include AIM, ICQ, MSN, and Yahoo compatability; presence detection; IM blocking; instant text messaging; instant text conferencing; message history; and much more. Other features include file-transfer and text-editing features, an enhanced gateway setup, enhanced text conferencing, shortcut keys, shared groups, and SSL support (these require Jabber Commercial Server 2.1), as well as the ability to cancel file transfers in progress, and more.

Requirements:

Windows 95/98/Me/NT/2000/XP