Random Numbers

Good random numbers are hard to find. It's nice to have a random number generator that continues to be random even when you take the modulus by a small integer to pick cards from a deck or simply test for odd or even to simulate a coin flip. This one is that good.

George Marsaglia's mother of all random number generators, written in Tcl.
A couple of C implementations of the same long period random number generator, along with Marsaglia's original announcement and explanation of the algorithm.