Of course I have seen it. A lot of it is the same free Bernstein libraries that have been used by Felix von Leitner, Paul Jarc, Laurent Bercot, et al., with some of the same C1999 modernizations; and that inspired various similar libraries.
* http://www.skarnet.org/software/skalibs/libstddjb/
>That said, I disagree with your premise that runit has bad code.
Have you seen it? Bad code may be subjective, but it certainly doesn't come close to my standards.