Deloria was programmed from scartch, although I've heard that it was the original ody source code changed. Even that doesn't make sence... the whole structure of gameplay is different.
Deloria, Im quite sure, was made with ORE 0.4, which is at www.baronsoft.com. Though, if online is too hard for you (gotta know what your doing in VB) then use either what Kaveh posted or DXRE which is at dxre.sytes.net =D