For educational purposes, I'd like to start with a POSIX compliant base, including a shell, basic utilities, and an ANSI C compiler, then see what kind of environments I can build by putting packages together.
However, most minimal POSIX conformant operating systems I've come across seem to be embedded and/or proprietary. Are there any such open source systems I can easily run under Virtualbox?
I have searched around a little about building such an environment from scratch, but it seems like it's a lot of work to simply get a bootable/usable environment, much less a a POSIX compliant one. I might try my hands at building a POSIX OS someday, but I'd first like to be a bit more computer savvy beforehand.
I think I have heard somewhere that Linux is not completely POSIX conformant, but as long as I can compile and build some of the more common and essential open source tools (like wget and w3m), I would be pretty happy, whether or not it used the Linux kernel. Same goes for the other basic components I would imagine might come with the operating system (e.g. glibc)