This is my favorite cellular automata. The simplicity and elegance that allows for such complex logic.
I ported the famous wireworld computer[0] to javascript a few years back[1]. The source[2] is in c# transpiled to javascript so it may be a bit hard to follow, but still an interesting read of how to squeeze every draw call out of 2d canvas.
[0] http://www.quinapalus.com/wi-index.html