I'd love to have the time and the resources to deal with more OSes. :) 20 years ago, I had to keep stuff running on Solaris and lots of other platforms. About 20 years ago, I still did some work on VMS on actual VAX hardware! It wasn't that long ago, that we had the possibility of BeOS either. Comparatively, we have quite a monoculture (of POSIX) these days with Windows being the non-POSIX representative.
Maybe unikernels like OpenMirage will help make things interesting.
And thanks! The work on Dylan is a lot of fun and keeps me semi-sane by keeping me busy.
But the world of operating systems is so much bigger than the desktop under the desk.
Good work on Dylan by the way.