skalibs is a package centralizing the public-domain C development files used for building other skarnet.org software. skalibs can also be used as a sound basic start for C development. There are a lot of general-purpose libraries out there; but if your main goal is to produce small and secure C code, you will like skalibs. skalibs contains exclusively public-domain code. So you can redistribute it as you want, and it does not prevent you from distributing any of your executables.