As a follow up to the earlier link regarding the performance of animations in CSS vs JavaScript, Christian Heilmann – Myth busting mythbusted:

Jack is doing a great job arguing his point that CSS animations are not always better than JavaScript animations. The issue is that all this does is debunking a blanket statement that was flawed from the very beginning and distilled down to a sound bite. An argument like “CSS animations are better than JavaScript animations for performance” is not a technical argument. It is damage control. You need to know a lot to make a JavaScript animation perform well, and you can do a lot of damage. If you use a CSS animation the only source of error is the browser. Thus, you prevent a lot of people writing even more badly optimised code for the web. Some good points that provide balance and perspective to the way web standards evolve and how to approach web development.