LynxOS can be seen on some of the high end linux driven cell phones and PDAs. IIRC, there was one PDA that was going to use the DE and switched to LynxOS at the last minute, just not sure which "partner" that was.
Plan 9 is very obscure however extremely tight on security. Makes for an awesome multi-user hub and spoke system. Set up a program server and n-tier it with another server, run a remote set of dumb terminals for user input or general use. I've never used it personally, but I've seen it mentioned serveral times in magazines like InfoWorld and such.
:pint:
