aerotwist

That's not quite true. Using a CSS transition on left, top, width etc requires a trip to the main thread, so it's no better of worse to do it with CSS than JavaScript. It is bad in both cases and should be avoided.

Equally animating transform and opacity changes with JS or CSS is normally the same. The only time we can do compositor only is when it's something like an infinite animation of something like a transform; that can be done without hitting the main thread. That rarely happens in real life though. Most apps and sites have way more complex anims going on.

Thank you!

Hope so! :) Feel free to let me know if you have specific questions, and if I can flow them into the podcast I will. I'd rather the episodes actually answered peoples' questions than be based on my hunches as to what's interesting or helpful.

It's using CSS 3D transforms not WebGL :)

The rendering is still done in CSS, which was the point, as opposed to using Canvas or WebGL. I wasn't trying to do everything in CSS, since that wouldn't actually be possible

I take your point, but however you choose to apply the CSS it's still CSS :)

Since CSS 3D transforms require the GPU you will need either Chrome or Safari running on a computer which supports GPU acceleration. Chrome on Windows XP, for example, does not allow use of the GPU by default so you wouldn't see WebGL or CSS 3D transforms