Chipmunk 5.0.0 is finally ready for general consumption! Head on over to the Github Project to get the latest source.

New features in no particular order:

• New joints/constraints system. Much more flexible and programable than before. Joints have adjustable parameters now so you can use them like servos and the like.
• Raycasting. Actually just line segment queries, but should be about as useful and is implemented very efficiently.
• New collision callback API. You now can register callbacks for collision begin/separate events among other useful things.
• Sensor shapes. Collision shapes that call callbacks but don’t generate collisions, like sensors in Box2D or triggers in Unity.
• API for safely removing objects from the space from callbacks.