Pidgin is a chat program which lets you log into accounts on multiple chat networks simultaneously. This means that you can be chatting with friends on XMPP and sitting in an IRC channel at the same time. Pidgin runs on Windows, Linux, and other UNIX-like operating systems.
Official site
Pidgin is a great client. I wish there was a mobile version of it!
Yeah, some mobile and OS X versions and it may really become “universal” , it was really quite good in its day - too long ago….