This would be a good open-source project
An Ada microkernel - the long-awaited APSE (Ada Programming Support Environment) could be built on it.
If it was designed and coded well, it could be used under Unix - eventually you could replace the c-based UNIX with a superior (faster as well as more secure) Ada OS. If you start with the microkernel then, over time, you can re-code the other parts, leaving things like the user GUI until last.
Biting the hand that feeds IT
