Hello.

Chipmunk 2D is a high-performance 2D rigid body physics library. It's been written in C++ and now, a Delphi translation is available, too.
Features
* Designed for 2D video games.
* Circle, convex polygon, and line segment collision primitives.
* Multiple collision primitives can be attached to the same rigid body.
* Fast collision detection by using a spatial hash for the broad phase.
* Extremely fast impulse solving by utilizing Erin Catto’s contact persistence algorithm.
* Support for collision callbacks based on object types.
* Impulses applied to contact points can be retrieved after the impulse solver has finished.
* Several kinds of joints available.
* C99 implementation, no external dependencies.
* Ruby extension available.
Screenshots
http://www.slembcke.net/photos/v/programming/chipmunk/
Videos
http://youtube.com/watch?v=sTHoWaTNJiA
http://www.youtube.com/watch?v=b6HvIDt1VSU
http://www.youtube.com/watch?v=Cx5GBMybxXw

Chipmunk 2D was ported to Delphi by Paul Robello. Here's the link to the headers:
http://www.sendspace.com/file/8ewkb7
And demos:
http://www.sendspace.com/file/x151lj

I'll try to post the most recent versions as soon as possible. Regards and have fun.