Quote from adric22 on December 8, 2011, 01:31
The best bet would be to take an absolute minimal linux kernel compiled with all of the drivers that the Raspberry Pi uses, leaving everything else out. Leave out a lot of the legacy unix stuff. Then build a new GUI that is not based on X in any way. Sort of like MacOS X, BeOS, AtheOS, etc. (yes, I realize the last two are not Linux, but they are POSIX compliant with proprietary GUI)
It would be wicked fast and use very little RAM.
The last 2? OSX isn't Lunix either it's unix-based