OS within an OS

Would it be possible to make my own mini OS inside a java application? Over the pass few days I've been working on UI stuff and then I realized I basically implemented my own blackbox environment which made me start to think that with a few modifications i could easily make it into a mini OS

>>14

By production level code, do you mean people writing code in Java which then executes in the JVM? If that's the case, I would consider that Java simulating hardware, but I guess the difference doesn't really matter. I would be very surprised if there was something in the vanilla JVM that simulates hardware, as it doesn't seem necessary to me and it would be inefficient, but I guess it is possible. Maybe it could be used to provide compatibility with services usually offered in hardware.