WebGL is currently is currently only supported in the latest builds of most of the browsers. It should be working in offical releases soon but in the meantime there is a little effort required to enable it.
Chromium
Chromium continuous builds for Linux, Mac OS X, and Windows. The most recent builds are available at:
Linux 32-bit: http://build.chromium.org/buildbot/continuous/linux/LATEST/
Linux 64-bit: http://build.chromium.org/buildbot/snapshots/chromium-rel-linux-64/
Mac OS X: http://build.chromium.org/buildbot/continuous/mac/LATEST/
Windows: http://build.chromium.org/buildbot/continuous/win/LATEST/
Download the latest viersion and unpack the file. Chromium also requires some additional command line switches to run:
Linux: ./chrome –no-sandbox –enable-webgl
Mac OS X: Chromium.app/Contents/MacOS/Chromium –no-sandbox –enable-webgl
Windows: chrome.exe –no-sandbox –enable-webgl
Firefox
On Firefox, WebGL is supported on the latest nightly builds:
Visit http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/ for builds on Linux (32- and 64-bit), Mac OS X and Windows.
To enable WebGL you will need to type about:config into the address bar, search for “webgl” and set the value of “webgl.enabled_for_all_sites” to true. The implementation does require OpenGL 2.1 drivers, there is a software rendering option which uses OSMesa but chances are it will be way too slow for most of the demos anywary.
Safari
WebGL is supported on newer version of OSX in the WebKit nightly builds available at
http://nightly.webkit.org/ .
Download and install then you will need to open the Terminal and enter:
defaults write com.apple.Safari WebKitWebGLEnabled -bool YES
This only needs to be run the first time and it will remember for the future.