> what other languages [...] give you the freedom to change the language and/or create DSL's [...]
FORTH. It's a very similar language from that respect. One of the first things you learn how to do as a FORTH developer is to rewrite the interpreter/compiler words.
I really like Forth and if I ever get into IoT that's what I would use over C any day. Forth works best from a clean slate though I think (from my admittedly limited experience), working in with a host OS takes a bit of fun away I found.
FORTH. It's a very similar language from that respect. One of the first things you learn how to do as a FORTH developer is to rewrite the interpreter/compiler words.