This is great, thank you! I've been looking for something like this: a simple small project that goes through all the involved phases and explains/demonstrates

This is great, thank you! I've been looking for something like this: a simple small project that goes through all the involved phases and explains/demonstrates the concepts, that I can mess around with on the weekends. It shouldnt be have real life applications, be serious or academically correct -- it should just be fun. I once found a blog post with an example of defining a grammar for a small language and then building an interpreter (in python i think) for it. It was really great, but I lost the link and can't seem to find it again. The same goes for OS'es - a simple but "end to end" walkthrough would be awesome. Anyway, cheers!