Ask HN: What is the difference between famo.us and cocoon.js?

I'm trying to understand the difference between these 2 technologies. I understand what famo.us is trying to do with its own rendering, but am new to cocoon.js. From what I read they started out as a game platform rendering on canvas, and were mainly geared towards the web, but have since announced support for HTML5 apps...hence trying to understand the difference.