About the Code
It is written in by Markus Persson (aka Notch), the creator of the popular game Minecraft.
It is a simplified port of Minecraft4k. It is announced by Markus on Twitter at twitter notch. The license is “You may use the code in here for any purpose in any way you want, at your own risk.”
some improvements for understanding. black and white, no camera movement http://jsfiddle.net/ter7G/, https://gist.github.com/antirez/4195130, by Salvatore Sanfilippo
another version for understanding. by alexhaefner. “I spent a moment and changed the arrays to Float32Arrays which have set sizes and sit in memory without being fucked with by the VM and sped the demo up dramatically.” http://jsfiddle.net/uzMPU/2612/