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.