Here's a WebGL-powered invitation to the GNU Hackers Meeting 2013, which is taking place in Paris on August 22-25 
http://www.beuc.net/demo-ghm/v1/
Free, hardware-accelerated WebGL support is recent under GNU/Linux, you'll need Mesa/Mesa-DRI 9 and Linux kernel 3.6 from Debian sid plus a recent Firefox, though a Mesa-software fallback is usually available in earlier versions. Meanwhile, here's a WebM capture:
(Curious about the capture process?)
Work is underway on an extended version of this invitation/demo, peek here