Here you can find research papers of the most important computer graphics conferences.
A good web page by Christopher Batty about the research in the area of physics-based animation. Here you can find recent publications, links to researchers as well as software and companies.
Bullet is a 3D collision detection and rigid body dynamics library for games. The library is open source and free for commercial use.
Open Dynamics Engine (ODE) is an open source, high performance library for simulating rigid body dynamics.
PyODE is a set of open-source Python bindings for the open dynamics engine (ODE).
PhD thesis of Raphael Diziol