ok here's a quick dump:

- https://en.wikipedia.org/wiki/PostScript

- language reference Adobe V3 https://www.adobe.com/products/postscript/pdfs/PLRM.pdf

- postscript as programming language http://www.ugrad.math.ubc.ca/Flat/lang.html

- First guide to Postscript http://tailrecursive.org/postscript/postscript.html

- L-systems in Postscript http://www.cs.unh.edu/~charpov/programming-lsystems.html

- The PostScript programming language http://www.cburch.com/csbsju/cs/portfolio/postscript.pdf

- Postscript Tutorial and Cookbook https://www-cdf.fnal.gov/offline/PostScript/BLUEBOOK.PDF

- PDF vs Postscript https://www.reddit.com/r/programming/comments/kssyt/postscri...

- Learn Postscript by Doing https://staff.science.uva.nl/a.j.p.heck/Courses/Mastercourse...