For me, the only software that I have used consistently since that era (~1981 or so) would be UNIX and the C programming language. And to be honest, I don't write that much straight C anymore.
It's a mix of C++, Python and Perl, plus writing documents in LaTeX, Org-Mode, etc. I enjoy programming in Common Lisp, too, but that's something I do mostly for pleasure. GNU Emacs has good support for programming in Common Lisp via SLIME.