libnih is a small library for C application development containing functions that, despite its name, are not implemented elsewhere in the standard library set.
libnih is roughly equivalent to other C libraries such as glib, except that its focus is on a small size and intended for applications that sit very low in the software stack, especially outside of /usr.
It expressly does not reimplement functions that already exist in libraries ordinarily shipped in /lib such libc6, and does not do foolish things like invent arbitrary typedefs for perfectly good C types.
These details are provided for information only. No information here is legal advice and should not be used as such.