ziOS is an Operating System made with the Cosmos C# framework, it's quick powerful and unique in my opinion.
Shell with multi-arg support
Shorter versions for commands in shell, for example LS could be typed as $
A minimalistic replacement for MIV called ziv
High-res console using PrismGraphics
Shell scripting
DVD-style screensaver
Command history
Tab completion
"Smart" terminal library
You should just be able to build with the Cosmos Dev Kit.