   any lib specifically for 2d?
  for physics and/or collision 
  You could use ODE:http://opende.sourceforge.net/It''s a 3d rigid body dynamics engine.  Check the mailing list archives as there have been posts on how to use it in 2D.cheerssam; it''s no lib, but both do collision and physics in 2D, in two different ways, if you''re interested in writing some physics.  soft body physicsrigid body physics