Before it was a media player, it was THE place to be for 56k online gaming.

MPlayer.Com
MPlayer Wiki

Summer of 1997, EVERYONE jumped on MPlayer ASAP after school. We played everything our computers could handle. We played all goddamn night, on a DIALUP connection. It was the beginning of the online gaming revolution that everyone takes for granted today. And it was all free. We were too young and dumb to realize there was only one way it could end. It sure was a great ride while it lasted. 

Wish I could get in touch with all the people I gamed with back in the day. Same goes for all those people on ICQ...

It was one of those "had to be there" things... I sure do miss it.