Rule 110
More often than not I find myself remembering I had forgotten that Rule 110 is actually Turing complete. It's beautiful though !
Proved by Matthew Cook, it simply means an awefully simple binary cellular automaton can solve any computable problem given an appropriate initial state. The picture above has its first line consisting entirely of one single dark pixel, the cellular automaton giving each subsequent line.
The thing is Turing completeness is transitive : if you can implement a turing complete system in another language it means the latter is also Turing complete. And now there is Eli Fox-Epstein implementing it in HTML+CSS3 proving the internet's basic layout system (look 'ma, without javascript !) capable of running every known program albeit in a slow fashion. So it was said that every program grows towards bloat until it is able to send mail, now it would seem every layout engine grows until it can run an amd64 VM, possibly. As long as it does not leak abstractions into a root sheel it should be all right. Keep eating ram you @#$ browser.