please visit neopangaia.com – the adult mmorpg/virtual planet earth
The first link here is to an RPG mod available for Unreal Tournament 3 (which includes persistent server and stats). They also have the source code available.
(former home of) A bunch of useful Unreal Engine 3 tutorials: quest creation, NPC conversation, and more.
If you are a UDK developer without UT3, you can get it (and any patches or the Nvidia PhysX Mod Pack) (will investigate)