Pidgin is a converse program which allows you log in to accounts on numerous chat networks concurrently. This means that you can be talking with friends on MSN, talking to a friend on Google Talk, and sitting in a Yahoo chat room all at the same time.
Pidgin runs on Windows, Linux, and other UNIX operating systems.

Pidgin is well-matched with the following chat networks out of the box: AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, Novell GroupWise Messenger, QQ, Lotus Sametime, SILC, SIMPLE, MySpaceIM, and Zephyr. It can support lots of more with plugins.

Pidgin supports lots of features of these converse networks, such as file transfers, away messages, buddy icons, custom similes, and typing notifications. Abundant plugins also expand Pidgin's functionality above and beyond the standard features.
Pidgin incorporate with the system tray on Windows.