Hurd libraries are very unusual. Little people has major experience with them, and they are very different from POSIX, or any other well-known standards. (this can be said about any other kernel's internals)
Idea: Please, everyone who wrote/saw any simple hello-world, that demonstrates use of any Hurd library (diskfs, libstore, cthreads, ihash, ...) or other non-standard facility (ex: of GMUMach), send it to single place, to facilate everyone learning GNU/Hurd programming. Before better place is found, the best is to place it anywhere on the Net and to send url to this list. Thanks in advance, Tomasz