This is my first submission to IOCCC, so I apologize in advance for anything I screw up. That being said, I'm pretty sure my program is "simple" enough that there shouldn't be any problem.
c99 yells some warnings at me but it and all other -std= that I tried work. I'm using Ubuntu 13 in a VM, but I've even gotten this to work with MinGW in Windows 7. However, it looks ugly in Windows. It should work on pretty much whatever as long as usleep() is accepted.
You will want the terminal at 64x33 (33 lines and 64 glyphs per line) in size for best effect. Bigger will work in a pinch. Run the program and watch until you get bored. When bored, CTRL-C or escape somehow. Run it again for a different starting pattern.
I'm sure you all know Conway's Game of Life already.
Read through remarks.txt if you want to see how it is done.