I made an implementation of SmoothLifeL in Ready and this video. Stephan Rafler created the SmoothLife rules and has his own software. Ready is designed to let the user play with a large range of systems like this one, connecting a field of floats to an OpenCL kernel that the user can rewrite on the fly. Check out Ready for some similar patterns, like Robert Munafo's U-Skate world.
There's a deep motivation behind all this, which is to try to understand the pattern formation mechanisms that appear in nature and get harnessed by organisms.
