The way it handles the HTML Canvas its awesome. Especially the animation using Sprite.

Very powerful library for web-based animations

The flexibilty of containers, depth sorting, animations through sprite sheets, object oriented interface, higher number of particle rendering and much more. I use almost all features of these and create games and applications. The preload.js library helps in preloading assets. Easy installation, and cross browser support that the library is being developed for is great. The great community that supports the queries helps resolve issues very fast.