tion percolala

A 240x135 grid of 64 instruction-length Brainfuck-like programs are randomly initialized. Every iteration, neighboring programs are randomly paired, have their instruction tapes concattenated together, and are run for a maximum of 2 13 steps. Once execution completes, the tapes are split back apart. The instructions are such that they can loop and mutate the instruction tapes (programs) themselves. As found in the paper, self-replicating programs that copy themselves over their neighbor's tape often spontaneously emerge, which soon spread to take over the entire grid.