http://www.cacophonyjs.com/ http://github.com/jbroadway/cacophony

And a basic demo video:

http://www.cacophonyjs.com/examples/demo.html

It's an interactive video player in Javascript using overlapping HTML5 video and canvas elements, a timeline, and a series of plugins to render visual effects or handle various forms of interactivity.

Interactive elements can be mouse-based or text input, pulling data in from external sources, and saving input from viewers to change aspects of the video over time.

I'm working on a video with this as an art project with a friend, but hoped that in releasing the player other artists can use it to make even better effects and things I never would have thought of.

(Note: Obviously inspired by http://thewildernessdowntown.com/ although I've been playing with some of the underlying elements for a while before that. They did show me what's possible and get me motivated to follow through! :)