To render 3D graphics in your web browser, you need a WebGL-enabled browser. Here's what we know:

• Chrome: Runs WebGL without modification.
  
  
• Firefox: To activate WebGL type about:config into the address bar, search for webgl, and set webgl.force-enabled=true.
  
  
• Safari: To activate WebGL in Safari 5.1, go to the Advanced section of Safari preferences and check "Show Develop menu in menu bar", then on the Develop menu check "Enable WebGL".
  
  
• Internet Explorer: Internet Explorer does not include WebGL, but there is a WebGL plug-in available here.

If everything is working, click the run button below. You should see two spheres orbiting each other at the bottom of this browser screen (you might have to scroll down to see them.)