Paper.js vector graphics in Javascript

For our Open Design project (later more on this) I need to draw flightpaths between objects in a browser window. After some searching I found help in paper.js. You can do amazing animations with it, have a look at this rainbow example.

paper.js rainbow example
It's HTML5 which might be a problem for our project, but it's a good example of what future web application might have in store.
From their about:
Paper.js is an open source vector graphics scripting framework that runs on top of the HTML5 Canvas. It offers a clean Scene Graph / Document Object Model and a lot of powerful functionality to create and work with vector graphics and bezier curves, all neatly wrapped up in a well designed, consistent and clean programming interface.