This is a heavy work in progress. The end goal is generic timelines that are not application- or environment-specific. For example, one dev may hook a timeline up to a 3D scene to control the camera rotation (using quaternions and spherical interpolation), another might hook the timeline up to animate CSS properties, another might animate the gravity and mass in a physics engine, or another might be using something else entirely.
The timelines can be bundled and easily re-used, swapped in and out, etc. Eventually there will be visual tools for designers to edit and import/export the timeline properties.
Tweening Arbitrary Paths in Canvas
CSS Property Tweening
Source and details to come.