Matter.js is a 2D physics engine for the web

• Rigid bodies
• Compound bodies
• Composite bodies
• Concave and convex hulls
• Physical properties (mass, area, density etc.)
• Restitution (elastic and inelastic collisions)
• Collisions (broad-phase, mid-phase and narrow-phase)
• Stable stacking and resting
• Conservation of momentum
• Friction and resistance
• Events
• Constraints
• Gravity
• Sleeping and static bodies