Yes indeed, and of course we must not forget Singularity&#x2F;Midori which were implemented in a derivative of C# and .NET<p>I&#x27;d really like an OS built this way to become competitive. 64 bit flat address spaces and fully type safe designs really let you simplify things a lot in some fundamental ways. And you&#x27;d be able to run existing Java desktop apps without much in the way of porting effort.<p>Unfortunately all the Java OS&#x27;s out there are hobby&#x2F;academic projects that never got very far beyond a basic window manager.