Ep is a project mainly written in PYTHON and GO, it's free.
Emergent Parser
Taking a cut at a few terms that parse themselves.
The path looks like this. A person types:
ep> foo bar baz
This sentence is tokenized into three terms: foo, bar, and baz.
All three are dispatched simultaneously.
Each term can communicate with all the other terms (or possibly only some subset).
They do a "handshake" where term foo says "I'm a verb or a noun" and term bar says "I'm only a verb" and term baz says "I'm only a noun."
Since a noun node must be adjacent to a verb node, the AST quickly settles into noun, verb, noun (A graph like this: o-o-o), and then the functions execute.