This looks fantastic. Pedagogically it makes sense to me, and I love this approach of not just teaching a language, but a paradigm (in this case, low-level systems programming), in a single text.

Zig got me excited when I stumbled into it about a year ago, but life got busy and then the io changes came along and I thought about holding off until things settled down - it's still a very young language.

But reading the first couple of chapters has piqued my interest in a language and the people who are working with it in a way I've not run into since I encountered Ruby in ~2006 (before Rails hit v1.0), I just hope the quality stays this high all the way through.