What, no seed on Math.random()? But I could've sworn...
The Mersenne Twister
It's here on GitHub, hopefully someone else finds it useful. The goal was to keep it concise and compact.
What does it do? It produces evenly distributed random integers between 0 and 4,294,967,296 (aka 0x100000000) from a seeded generator.
BTW: If anyone is an expert in cryptography or mathematics please review my implementation.