Benoit Jacob from the platform engineering team has a blog post on how to best take advantage of hardware acceleration and WebGL in Firefox 4, namely: Upgrade your graphics drivers!
Firefox 4 automatically disables the hardware acceleration and WebGL features if the graphics driver on your system has bugs that cause Firefox to crash. You still get all the other benefits of Firefox 4, of course, just not the newest graphics features. But for best results, you need an up-to-date graphics driver that fixes those bugs.
- Windows users with Intel cards: you need a very recent driver.
- Windows users with NVIDIA cards: you need driver version 257.21 or newer.
- Windows users with ATI cards: you need driver version 10.6 or newer.
- Instructions are also given for Mac and X11 (Linux/Unix).
If you’re planning to develop using WebGL, you need to also spread this message to your users, so they will be able to experience the awesome results of your hard work.