Why not FORTH? It may not have some features out of the box (no type checking - which isn't as bad as it sounds with FORTH) but newer runtimes tend to put those things in and/or are fairly easily implemented yourself.
FORTH is neat, but I think you need to be too smart to use it. I made a list of other things I want under the peer post about LUA, some of that applies to FORTH.
https://en.wikipedia.org/wiki/Forth_(programming_language)
also, system level REPL is some hardcore nerdity.