Existing monolithic operating systems have been made obsolete by advances in hardware capability and continually falling prices, together with advances in programming techniques and networks, both local and wide-area. Instead I advocate for an architecture that has no centralized operating system, hence the un-OS, or UNOS.
The attempt to banish monolithic operating systems is no mere intellectual exercise. There are real, good, reasons to suppose that monopolies such as that currently owned by Microsoft are hindering the evolution of technology. And I see no logic which suggests that replacing Microsofts monopoly with some other, such as Linux, or even a situation with a few large players, will make things more than marginally better.
Also, the UNOS provides a solid platform for and depends intimately upon a high-performance object-oriented software system. UNOS and UNOS applications consist solely of collections of interacting objects.