Just wanted to share that this is one of the best tutorials that I've read in quite a while! Super clear writing style, the use of diffs for each stage (as well as showing the progression via different tags in the repository) is incredible (and something I may borrow in the future!), and you do a great job walking the reader through the complexities of Rust in an approachable way. Really, really cool.
I haven't read about hecto (yet), but I can thoroughly recommend the one about kilo, which is linked in the first paragraph of that article http://antirez.com/news/108 . Or even just reading the C code. It's achieving a lot with few lines and no dependencies (outside of the OS, that is)