After talks broke down with Quake Innovations who had created the qwpball modification for quakeworld, Calrathan set out to create a paintball mod for Q2 without QI's help. Calrathan acted as project lead and lead programmer and jitspoe was the 2d/3d artist and mapper. They produced their first beta in almost record breaking time (20 some days). Then other people became involved (SmokeYa, TX_Outlaw, TiGeR, Sad and a couple others I'm missing) to bring the game towards a 1.5 release. After 1.5 Calrathan was busy with college, but jitspoe still found time to maintain the code to do mostly maintenance fixes (speedcheat/zbot detection, gl_modulate cap, bug fixes). Once the Q2 Engine SDK was released jitspoe used the BeefQuake engine and started building the DP as we know it today, almost exclusively.
If you want a history lesson, go read the news section and read the archives starting from July '98 to present.