I found this little os that is still in alpha stage and tested it under vmware. The GUI is a copy of the one from Beos. The kernel is only 98kb. I don’t have the slightest clue what file system it uses. Only thing I know is that it’s not posix compatible. Another similarity to haiku is that when it boots the first thing u see is the terminal.
This is the homepage : http://monaos.org/about.html
I checked out this and its still alive. Higepon (the main developer) still seems working hard making the MonaOS better in his blog (it reached version 0.1 recently). It must be very interesting…
AFAICT, the GUI actually has a skinnable interface. Not only does it have the BeOS clone look using what I think are probably SVG icons, it also has a MacOS (8?) clone, as well. It even has a client-server architecture like BeOS does, but that seems to be where a lot of the similarities end – the look and the general architecture.