> Free but not Open Source? Did I miss that?

The miniscript language itself is MIT License:

https://github.com/JoeStrout/miniscript

The Minimicro code doesn't seem to have any license in the repository or code:

https://github.com/JoeStrout/minimicro-sysdisk

So Open Source but not Free (Libre).

For miniscript: the Free Software Foundation considers the MIT license (which they call the ‘Expat License’ to distinguish it from the ‘X11 License’) to be ‘free’ (and GPL compatible), but not ‘copyleft’.

https://www.gnu.org/licenses/license-list.html#Expat

For minimicro-sysdisk: I am suspicious that the author just forgot to include a license. Their other repos are mostly MIT or ‘The Unlicensed (also ‘free’ but not ‘copyleft’), and some have licenses added after creation. Suspicion is not something to be legally relied on of course…

That's usually called "source available", since most people, including some governmental orgs around the world, already follow OSI's definition for "open source".

Am I the only one that hates that programmers now have to also be lawyers?

What do you mean now? The peak of debating the merits of varied FOSS licenses must have been 20 years ago.

Mini Micro seems to be built on Unity. The MiniScript portion of it is open source https://github.com/JoeStrout/miniscript but the version packaged for use by Unity costs some money. I can't tell if the people behind MiniScript are the same people behind the Mini Micro.