Miranda IM

Miranda IM: Multi-protocol instant messenger client

Miranda IM is a free multi-protocol IM client for Windows operating systems that uses few system resources and is very fast.
Miranda IM occupies less space on your computer than a floppy disc and doesn’t require installation.

The program is equipped only with essential features but has a flexible architecture thus its functionality can be expanded through plugins.
Miranda IM supports a large number of protocols such as ICQ, AIM, MASN, Jabber, Yahoo, Gadu-Gadu, Tlen, Netsend and others.