I got a copy of Jazz Jackrabbit 2 sometime in 1997. I played the 'party modes' a lot in splitscreen with my brother (then going by the alias Jaws, now Lord Trilobite) and later I also started playing online.
I started making some levels and eventually I started experimenting with tileset making. The result was the Paint tileset. It was okay for a first try but nothing incredible. The Lost World tileset on the other hand, which I made with my brother, was a lot better. Christmas 2001, we released the Lost World Episode, a singleplayer level-pack which recieved quite a few really good reviews.
I also helped create tutorial site Howto JCS, which was originally part of the "Rabbits Only" website, founded by Newspaz and myself.