I just updated some old Elm code from 0.17 to 0.18. The code is used to simulate a Universal Register Machine, the gif below shows the addition of two numbers. If you would like to run your own URM-code just copy the code from the gist to elm-lang.org/try, change the program inside the Elm snippet and update the registers as you like.
I sketched this program while I was listening to the presentation at ClojureD. I think it is a powerful and seldom recognized feature of Elm, that it is easy to visualize things, e. g. complex behaviors.