Forth-likes are very very simple to bootstrap in basically any environment (contributing to their popularity back in the age of microcomputers sold with no OS), and once you’ve accepted the syntax are perhaps the most lightweight environments for doing DSLs (which is somewhat related, as one of the typical bootstrapping paths has you writing an assembler DSL as one of the first steps). The “postfix Lisp” PostScript/Joy/Factor heritage that TFA’s language belongs to inherits the latter property.

If I had a choice of making and then using a DSL in Python, Lua, or Forth, it’s Forth all the way, no question. Now if you include Scheme, Ruby, or Tcl, then it might become a competition. (Haskell is somewhere in between.) It’s worth appreciating how much above his weight the humble granddaddy is punching here for the dozen K of memory that a running system normally takes. (Less relevant now than for the micros of old, as for interactivity that memory needs to be RAM, whereas the cheapest controllers today are usually ROM-rich and RAM-starved, relatively speaking.)