In order to check whether your browser supports WebGL, visit
http://get.webgl.org/
Linux and WebGL have teething problems, and in many cases it just does not work.
Whenever there is a support question, you need to provide
- what graphics card you have
- which driver you are using (mostly if they are the free/closed ones for ATI or NVidia). Newer Intel graphics drivers may be supported, older are quite unlikely.
In most cases you can force your browser to use WebGL; follow the link that it given when you visit http://get.webgl.org/