need a free opengl 3d engine (Windows)

Hello
I’m looking for a free opengl 3d engine for windows
(support mingw c++)
It must have a big communitiy, …mailinglist, forum, a lot of tutorials… like genesis oder crystal space
any ideas ?
thanx

Open Scene Graph?
http://www.openscenegraph.org/

OK, I will bite, whats wrong with Crystal Space? It seems to fit your qualifications.

To Elixier : Yes you are right.
Crystal space is 100% OpenGL compatible , I was not sure about that. This point is not good expained in the cs tutorials.
I think, I will use Crystal Space.
Its free, support opengl, big community, works on linux and windows. also with mingw. (i dontt like this visual stuff)
greetings
fab