I also liked the color scheme.
I only wish I could be as diligent and focused to do a thing like this, because I think it would be so much fun. I bought the Crafting Interpreters book a while ago, but still haven't got time to actually go through with it.
Well, maybe one day...
[…]
mmap is awesome but Linux's got something even more awesome: mremap, which makes it almost trivial to manage the page-based heap.“*
⇒ they are using “freestanding” in a non-standard way. Usually, it means running on bare metal without an OS (https://en.wikipedia.org/wiki/Standalone_program: “A standalone program, also known as a freestanding program, is a computer program that does not load any external module, library function or program and that is designed to boot with the bootstrap procedure of the target processor – it runs on bare metal”