WebGL is a context of the canvas HTML element that provides a 3D computer graphics API without the use of plug-ins.
After recent installation of firefox 4 i am getting the following error message
This Browser does not support WebGL
First you need to install the following package
sudo apt-get install libosmesa6
After installing above package open your browser and type about:config address bar and search for webgl.osmesalib now you need to add string type as /usr/lib/libOSMesa.so.6
Finall restart your firefox
You can check if webgl is working or not go to https://demos.mozilla.org/en-US/ and play 360° Video.