Just bash, the command-line tools one uses from bash, LaTeX, and emacs/vim. I think git will stick around for decades even though its predecessors didn't.

My machines pretty much run Emacs, LaTeX, and Firefox, and everything else is largely window-dressing[0]. (I end up doing most of my command-line stuff from eshell inside of Emacs these days.)

[0] Well, a WM/DE of course, either Stumpwm or Plasma. And pdfpc[1] is really pretty fantastic for showing "Beamer" (pdf) slides. And syncthing for sync'ing between machines.

[1] https://pdfpc.github.io/

On Windows, some file managers are in this category. E.g. Far has been around for about 25 years now, and still has a cult-like following, especially in Eastern Europe / ex-USSR.

ImageMagick is another one that has been around for almost 30 years, and is the Swiss army knife of batch image processing on any platform.

you get me to think about guys like Game of Thrones author, who writes in WordStar 4.0 for DOS :)

And in a way.. MS Office has been forever, even though it changed a lot in the recent years .. Excel is still Excel.

On file managers: Norton / Midnight Commander.

Well, you won't really see anybody using the original NC outside of DOS emulation. Midnight Commander and Far are spiritual successors, hence why I'm counting from mid-90s for them, not from mid-80s.

I suppose it could be seen as vi to Vim, though.

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.

What language do you write now?

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.

make is for better or worse, forever.

John McPhee has written using a customised version of Kedit since the early 80s.

https://www.kedit.com/index.html

https://www.newyorker.com/magazine/2013/01/14/structure

There's vi/vim of course.