bspView rendering quake 2 BSP maps in the browser.krenz.tastyspleen.net/bsp/
NOTE: This software utilizes the webGL 3D Graphics API so you'll need a fairly modern browser with webGL supported. I recommend either the Google Chrome Developer or Google Canary Builds.
yeah it was written by this brilliant guy, brandon jones - http://blog.tojicode.com. Another demigod of graphics programming. I came across his site while learning about some webGL stuff.
Writing shaders is one thing, but parseing and compiling bsp files takes things to a completely different level.
By the way, what do you think of WebGL?