Lisp, and specifically Common Lisp although the latter isn't that old.
It first appeared in 1984 and the ANSI specification was finished in 1994, but it traces its lineage directly back to Lisp 1.5 from 1962. It can run Lisp sources decades older than it trivially.
It is a very practical, multi-paradigm language with high quality, high performance implementations on many platforms.
Its main issue is that it is not very popular, but that might also be a blessing.
It first appeared in 1984 and the ANSI specification was finished in 1994, but it traces its lineage directly back to Lisp 1.5 from 1962. It can run Lisp sources decades older than it trivially.
It is a very practical, multi-paradigm language with high quality, high performance implementations on many platforms.
Its main issue is that it is not very popular, but that might also be a blessing.