I am using Firefox 4.0RC1 from the Mozilla Team's "Firefox Next" PPA.
My about:config has webgl.enabled_for_all_sites
set to true as most guides recommend that and also say that is all that is needed. It doesn't work for me.
The main Mozilla Demos page ("Web O' Wonder") gives me:
Unfortunately, while your browser supports WebGL, your video drivers may be too old. To view any of the demos tagged with WebGL, try updating your drivers at NVIDIA, AMD, and Intel.
You can still watch screencasts of the WebGL demos or fully experience our other non-WebGL demos without updating.
My laptop (a Thinkpad x200s) has an Intel GMA 4500HD chipset and my xserver-xorg-video-intel
version is 2:2.12.0-1ubuntu5.2
This Mozilla demo gives me "No WebGL context found."