Havok - is a famous physics engine, with its help were made popular games such as: Assasin's Creed, Hellgate: London, Painkiller, Painkiller: Overdose, Stranglehold, Test Drive Unlimited, The Godfather, The Simpsons, Timeshift, Tom Clancy's Splinter Cell Double Agent , Urban Chaos: Riot Response, World in Conflict, HALF LIFE 2, etc.
In the package of AAA-technology includes such tools: Havok Animation, Havok AI, Havok Behavior, Havok Cloth, Havok Destruction, and Havok Physics.
The engine represents a completely professional tools for creating full-fledged games of the highest quality.
At the moment it is laid out a free package of PC-version of the engine Havok. The free version will serve you a good example, it includes a physics engine Havok, a package of animation, level editor, etc. You will be enough to create his own game.
The only thing that may disappoint all the fans, necessarily requires the ability to program in MSVC + + (all the libraries are attached, there is reference). In general, if you're willing to explore engine and all you need to create games in it, the flag in your hands, as it is a complete professional tools.