Novodex
Novodex is the default physics engine for UnrealEngine3
Content
Links
http://www.novodex.com/downloads.html
There is also Karma and Havok physics.
Discussion
OlympusMons: Didnt really know what to put here so I added the links to the novodex sites.
El Muerte: you know, there are much more physics engines than just the late Karma and Havok.
OlympusMons: Yeah I know I just figured those were more relevant to unreal engine development.