Concrete
Concrete is a lightweight, fast Html5 Canvas framework that enables hit detection, layering, multi-buffering for lightning fast performance, pixel ratio support, and download support
As the creator of KineticJS, author of HTML5 Canvas Cookbook, founder of HTML5CanvasTutorials.com, founder of MeteorCharts, and the principal data visualization engineer at Platfora and Workday, I've identified a handful of features that just about every HTML5 Canvas project needs. Concrete packages up these features into a lightweight framework of about 600 lines of JavaScript, including documentation.
Examples & Documentation
Head on over to the main website http://www.concretejs.com.