Miranda IM - (Open Source)
Miranda is a great instant messaging software, compatible with most existing software such as ICQ, AIM, MSN, Jabber, Yahoo, IRC, Gadu-Gadu, Tlen, Netsend.
Miranda is a very flexible instant messaging client for chatting on multiple networks simultaneously. It is able to connect to ICQ, AIM, MSN, Facebook, Jabber, Yahoo!, Gadu Gadu, IRC and some other protocols.
The purpose of software is to make this kind of communication as simple as possible. It is also possible to copy Miranda on a USB stick or other removable.
Miranda is also customizable with many other plugins and skins, and boasts a very active community.
Enhancements
* Improved account deletion support
* MSN: Non IM contacts removed from the contact list and database
* Yahoo: Removed Show Profile for non Yahoo contacts
Bugfixes
* Fix for ssl errors when client tries to send on closed connection
* AIM: File transfer fixes
* IRC: Own actions were not always shown
* Jabber: Random disconnect issue caused by timeouts
* Jabber: Fixed encrypted messages being empty (XEP-0027)