It is interesting that one of the most solid piece of software component that is relatively resistant to rotting is Shell/Bash scripts. (Including Makefiles)

Python, Ruby, etc. constantly get obsolete over time, packages get removed from the central repositories, ceasing to work.

Obviously shell scripts contain _many_ external dependencies, but overall the semantics are well-defined even if the actual definitions are loose against the shell script itself.

P.S: I have written couple of Bash-script projects that are still running (mostly deployment automation scripts) meanwhile, some of which I was being "smart" and wrote them in Python 2.7, unfortunately ceased to function, requiring upgrades...