It is standalone version of argp - part of glibc library.
It was separated off glibc by Niels Myller, Niels primary use
it for inclusion in the LSH distribution, but it's useful for
any package that wants to use argp and at the same time be
portable to non-glibc systems.
Besides portability fixes, there are a few other changes in
this version. The most important is that it no longer builds
upon getopt; the one or two hairy functions of GNU getopt are
incorporated with the argp parser. There are longer any global
variables keeping track of the parser state.
PR: ports/63568
Submitted by: Sergey Matveychuk <sem@ciam.ru>