Something must be wrong with their feature detection 'cause all I see in Chrome and Firefox are some well-rendered sky and engine lights. Linux, Chrome 19, Firefox 12, nouveau drivers.
And no, I'm not overriding anything, it's always just worked.
Edit: In fact, doing a quick grep through the shipviewer.js file, they're only using GL_ARB_texture_cube_map plus a bit of framebuffer drawing, both of which are fairly standard things and should be supported by gallium. No idea what the issue might be..
The engine lights do look pretty though.