[jerf]

It basically is just the JVM. In terms of longevity, we don't have to limit ourselves to just what one programmer can bang out in half a year from an absolute standing start. We can also include existing code. Existing VMs that work to minimize their footprint and are thus portable to other things relatively easily meet the bill fairly well in the real world, actually.

x86 assembler is likely to be around for a very long time too. It may not be the simplest, but it doesn't have to be, because it's already been implemented several times, in open source.

If I look back at why code doesn't run, by which I mean, real programs that I really wanted to run from the past, this isn't the core problem. I've never failed to run something because the lowest level wasn't working. If nothing else, emulators do a good job of lifting & isolating the underlying hardware and software environment. My problems have been lack of physical hardware, integration with dead OSes (in that dead zone between "the OS is obsolete" and "emulators exist for it now"), changes in input and/or output formats over time (no DOS program from the 20th century knows what to do with a chunk of JSON, no existing program knows what to do with the semi-standardized neural net format from 2052) and the one the article does mention, missing dependencies, even for binaries.