[shabble]

You could potentially store them inside/along with a virtual machine image which would be capable of rendering them, and then document the crap out of the VM (which would require as few, and as simple, external interfaces as possible), such that it could be easily re-created/ported to future OSes.

I think quite a few places where continuity over decade timescales (especially in the embedded world) are storing VM images with the exact versions of various parts of the toolchain they use, to ensure compatibility.

And of course, there's plenty of precedent with things like the Hercules IBM mainframe emulator[1], as well as things like VMWare, Bochs, QEMU, etc.

I think I've come across old DOS games being re-released wrapped with dosbox or something similar as a compat layer for modern OSes.

[1] https://en.wikipedia.org/wiki/Hercules_%28emulator%29