3D Boolean CSG on Geometry Libraries?

I’m trying to complete an OpenGL based project and I require some general purpose CSG modeling features to pre-compute at runtime. Specifically operating on the geometry, not frame buffer tricks.

While I’ve searched these boards and continually find posts here and there strongly suggesting using already available 3D Boolean CSG libraries (because of the special case complexities), I’m yet to run across a post that lists any of these libraries.

Do any of you folks use or recommend third-party (commercial or open source) 3D Boolean CSG libraries (for C or C++ please)? If so can you list them here?

-or- any pointers to algorithms or tutorials for performing diffs between a mesh and another mesh would be much appreciated.

Thank you in advance.