This uses a single assembly machine (plus two for barelling, more on that later) to build any item in the game, and automatically compute & build all the intermediates in the same machine. The crafting combinator viewtopic.php?f=93&t=34405 is used to switch recipes and compute intermediate products.
Practical? Of course not. But it was a lot of fun and taking on the challenge made me feel good about my theory of computation class in college (anybody need a context free language parsed in factorio?), as well as learning a lot about combinators.