Miranda IM v0.7 Build #3
Miranda has reached version 0.7 Build 3 (it is a test build). Stable version is 0.5.1. You can read about the test build on this page: http://www.miranda-im.org/2006/11/26/miranda-im-v07-build-3/
Miranda is a universal messaging client supporting a variety of protocols including ICQ/AIM/MSN/Jabber/Yahoo/IRC/Gadu-Gadu/Tlen/Netsend. It has a large number of plugins available as well. Plus Miranda is fast and does not waste tons of resources like original ICQ and MSN clients do. You can find screenshots made by various users on Miranda screenshots page.