From Miranda IM
iranda IM is a multi-protocol instant messaging client for Windows. Very light on system resources and extremely fast, Miranda IM requires no installation and can be made to fit on a single floppy disk or USB drive. Featuring a powerful plugin-based framework and boasting over 350 plugins, Miranda IM is one of the most flexible and customisable messaging clients on the planet.
* AIM (AOL Instant Messenger)
* IAX (Inter-Asterisk Exchange)
* IRC (Internet Relay Chat)
* Jabber: Disable TLS in the Facebook Chat account type
* Yahoo: Improved offline messaging support for Meta plugin