Features:

• Rigid Body physics with Buoyancy and a variety of Constraints.
• Convex-Polygon and Circle shape types.
• Powerful, high-level Callbacks system.
• Pixels as units of distance.
• Continuous Collisions/Sensing to avoid tunnelling.
• An API that reports errors when used incorrectly. (Error checking and reporting disabled for release builds.)
• Automatic handling of sleeping/waking, no general need to ever wake a Body manually.
• Friendly, expressive API that uses a lazy implementation to avoid excessive calculations.
• Fast!
• Memory conscious implementation, no GC activity when used correctly!
• Numerically stable Geometric utilities including Convex Decompositions.
• Ability to create new Constraints without modifying Nape source. Through the symbolic module, can prototype new constraints using a high-level language specified at run-time.
• All positional-constraints, including user-defined ones can be made elastic or stiff.