Instant Bird is Multi Protocol Client supports of AIM aka AOL Instant Messenger, MSN Messenger aka Windows Live Messenger, YM aka Yahoo Messenger, GTalk aka Google Talk, Gadu gadu, ICQ, IRC, QQ, XMPP that works for Windows Platform, Mac OS X and also Linux.

Features available in InstantBird: Chat Room, Contact List, Tabbed IM Windows, and many more. It’s developed by Mozilla Teams that also create Mozilla FireFox, Thunderbird and more.
Download Page: InstantBird
License: Free / Open Source
Website: www.instantbird.com

Short Review: Pidgin is Multi Protocol Instant Messenger Client that supports AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, Novell GroupWise Messenger, QQ, Lotus Sametime, SILC, SIMPLE, MySpaceIM, and Zephyr. For further information about Pidgin you can read my article discussing Pidgin here.
Portable Pidgin is Pidgin Chat Client that designed works with portable devices without need to install to run it or use it. Just run from the portable device where the pidgin portable file exist then you can use Pidgin just like you use official Pidgin …