I think I first used it ~1995 so that would be 22 years.

Hung around for about 5-6 years and it's been around in the background ever since, just got back into using it recently as one of the frameworks I use has a decent IRC channel and an even more decent offtopic, nice bunch of folks and with the ability to throw it in the background it gives a water cooler feeling when I'm working on my own and need to bounce an idea of people.