Continued development of OJP/JKE just isn't feasible.
It was good back in the day. A nice mod to play, a good place to learn and contribute, but..that died out.
People ended up using it entirely just to take code/content from and claim to be modders, never giving anything back.
The team just decided "Whatever. No interest" etc, but we all wanted to continue working together.
So we took a peek around a few engines, and decided to develop a game using the C4 engine.
The OJP/JKE source is still available, though not even I know where the latest build is.
Try asking 'Judge' at www.jk-rp.com
if he knows anything if you're interested.