Tossing my hat in for Passerine [1]. Gorgeous ML inspired syntax. Written in Rust, and I suspect scripting Rust libraries is in the cards.
Dreaming here: Lua is a fantastic scripting language, but the Rust FFI isn’t as ergonomic as it could be. Enter Luster [2], which is basically LuaJIT rewritten in Rust.
Embedding a scripting language in a Rust application gives you tons of power (e.g. scripting Rust structs from Lua [3]), and setting this up isn’t terribly difficult.
[1]: https://github.com/vrtbl/passerine