There's a lot to be said for the stability of old platforms where the language and libraries are fixed. In a world where hardware has to run fast to deal with software bloat, developers can also choose old and slower languages to get okay-ish performance.
I wrote a simple software using an old programming language (Common LISP ANSI is from 1994), the result is that it's reliable over time, require no code maintenance and is fun to code on.
And for an even further back blast, witness @jcs hacking on system 6.
Now if only these old platforms could get security updates....