Tribblix is an operating system derived from OpenSolaris, OpenIndiana, and Illumos, with a retro style and modern components.
NEWS: September 29th 2015: Milestone 16 released, with many updates. This updated release initially available for x86, a SPARC version will be along later. (Release Notes.)
It's proved that the concept can work, and while it certainly isn't fully functional, complete, or yet recommended for production use, it's getting closer. You can download the image, install to a hard drive, and use it.