I've been looking at a program gfind, that searches for spaceships in Conway's Game of Life. The documentation says a bunch of stuff about searching De-Bruijin graphs. I couldn't find any useful information about these on the internet, I couldn't figure out how they could be searched, and I'm too broke to get a book. I also looked through David Eppstein's paper [1] on the matter, but it still was too cryptic. I just need an explanation at a high-school level (even though I'm in middle school O_O) of how the algorithm works.
[1] Searching for Spaceships, David Eppstein http://arxiv.org/abs/cs/0004003