I've written both Forth and Lisp for production systems. Both are very intolerant of lax software engineering practices. Because both are "language construction

I've written both Forth and Lisp for production systems. Both are very intolerant of lax software engineering practices. Because both are "language construction kits," you have to come to agreement with other members of your team about how you will create and document your DSLs, which is a step beyond the agreements you need with "ordinary" languages. The big difference for me was that I couldn't even read my own Forth code after I had been away from it for a year; I had to first re-teach my brain to think like a stack machine. That was never a problem with Lisp. I can look at 10-year-old code I wrote in Lisp and re-understand it quickly (especially with the tools built in to Emacs that are quite helpful for Lisp code exploration).