[dualogy]

Stumbled upon this a while ago while looking for "a systems Scheme", but abandonware in my book given the most recent commit date (and GH Issue).

Settled on Gerbil Scheme instead, lively community & been actively developed to this day for over 15 years now. Although fair warning, still GC'd and (for now) only type-annotated, not (100%) statically typed. But stdlib-wise and compilation-wise still way more "systems-bent" than most Schemes out there.

[davexunit]

Guile is quite systems focused, as well, what with all the POSIX stuff it exposes. But neither Guile nor Gerbil can be used to implement their own runtimes. You need to write the GC, somehow. This is why Pre-Scheme exists.