A simple tween library in javascript that can tween anything by properties, but must be manually updated (custom setInterval or requestAnimationFrame call)
If you build browser games, you want to be able to control how the system updates. All game entities should update at the same time so any interactions can be resolved.
You can find some canvas examples by looking at index.html. This tweener uses properties, so can be applied to anything; canvas shapes, DOM elements, even the browser properties itself.