I'll throw two domain specific language (families) into the mix, that are psuedo-dead although not really dead.

Although amstex and latex are healthy (and latex is about 40 years old) I would argue that very few indeed are writing in raw bare macro-free package-free tex, just bare totally raw tex. I'm sure it happens... rarely.

Another psuedo-dead is postscript. In the 80s there was a famous EE pushing the idea of sending your code and data to your postscript laserprinter as a batch frontend sorta and let the laserprinter interpret the postscript and do the calculations for your smith chart, not merely print your bitmap containing a smith chart or whatever. That idea of postscript as a general purpose application language, although infinitely cool, never went much of anywhere.