@dan the code quality in busybox is awful. it seems small, but a lot of it is calling a bunch of libraries too, and the style is just quite cumbersome, overall it's about the same code size as equivalent openbsd code with non-posix features removed to match busybox functionality
openbsd code style is very clean, it almost feels like you're reading a book
compliance/liability issues with busybox code due to GPL license (and from what i've gleaned, conflicting GPL 2/3 licensing depending on use)