It just resulted in the open and official fork - OpenSIMH[1].
Also notable SIMH[1] emulator to run various ancient architectures.
Also would be nice to run it on SIMH[1].
The site documents SimH, a simulator for historic computer systems, as well as papers and reflections on the history of computing.
code is here: https://github.com/open-simh/simh
It's the only modern OS that can still be also installed on VAX. You can try it yourself with OpenSIMH[1][2][3]. I struggled to successfully setup network though - for some reason it wasn't working as expected.
[1] https://github.com/open-simh/simh/