The author using FizzBuzz as a comical-but-recognizable launching point for demonstrating introducing the basics of programming language implementation and RPLY, and the HN comments being nothing but people yelling about FizzBuzz, is a pretty amazing summary of the state Hacker News comments. It also makes me think next time I have a technical article, I should prepend some controversial statement to it just to generate buzz :V

In all seriousness: this is a really cool article, thanks for sharing! I'm not very familiar with RPython or RPLY and it was really cool to see a "real-world" example of it. I actually just read through something similar in JavaScript (https://github.com/thejameskyle/the-super-tiny-compiler). I really should give language implementation a shot one of these days (closest I've come is writing a JSON lexer & parser); always like to read about it!