Gleam is a statically typed language that runs on the Erlang virtual machine. From distance, it looks like a love child of Go and Elixir (count me in!)

One neat language feature is a todo keyword. First-class syntax to mark a piece of code as work in progress and to stop the compiler from yelling at your half-implemented code.

fn favourite_number() -> Int {
  // The type annotations says this returns an Int,
  // but we don't need to implement it yet.
  todo
}
 
pub fn main() {
  favourite_number() * 2
}