Nyx sounds fine to me too (as does Erebus). I assume you have considered and determined to not be too significant that many people use *nix (sp?) when they want to refer generically and collectively to various flavors of Unix-like OSes.
Thanks Paul! Yup, *nix is something I considered (and mentioned on this thread). Agreed that verbally they sound identical, but in writing probably won't cause much confusion. Should be fine.
Cheers! -Damian