Firefox 4 Beta 8 released with WebGL activated by default, WebGL brings 3D graphics to Firefox 4 opening the door for developers to create vivid games and new kinds of visualizations and experiences for the web. Mozilla claims Firefox 4 supports WebGL for a large number of built-in graphics cards on Mac and Windows.
If you are experiencing any issues while trying the Demos of WebGL in Firefox, check you’ve installed latest DirectX drivers from Microsoft and ensure your graphic card supports OpenGL 2.0 drivers. If you wish, you can disable WebGL in Firefox 4, here is how.
Disabling WebGL in Firefox 4
1. Type about:config in Firefox address bar and continue with the warning dialog.
2. Type ‘Webgl’ in the Filter box double click “ webgl.enabled_for_all_sites” and set its value to ‘False’.
3. Restart Firefox browser, WebGL is now disabled in Firefox 4.
Update 11/05/2011 : In Firefox 4.0.1 “webgl.enabled_for_all_sites” preference has been changed to “webgl.disabled”. Double click Webgl.disabled entry and turn its value into “True”.
Also read how to disable WebGL in Chrome (just posted).