Bebu Silver badge
Windows

I am not too sure...
about the "immortality" of FOSS code.

Looking at the C code in Lions Unix (v6) commentary the code is pretty rough by any standard and certainly when compared with contemporary Linux and BSD code. I imagine in 50 years time that code will look peculiar too.

Long ago having ported quite a lot of open source code between System V and BSD systems (and from VAX/VMS) I can say a lot of it was pretty ghastly and could only be immortal in the sense of a vampire or zombie.

Scientific and Engineering Fortran code, mostly numerical analysis or numerical algorithms does seem immortal. I have had to deal with 40+ year old fortran source which with a bit of compiler tweaking and a couple of (automated) edits compiled cleanly and passed its test suite.

Whether Rust, Go etc etc are still in extended use in 20 years time is probably 10:1 against.

PL/1, Simula67, and even Ada while not gone aren't exactly in common use.

Human perversity will probably ensure people are still hacking away in ISO C42 and using -std=c89 to retain K&R function definitions.

I suppose I could reimplement coreutils in SPARK (Ada). ;)