Have you heard of Teal (https://github.com/teal-language/tl)? It's like typescript for Lua made by Hisham. It also has the concept of declaration files so you can import (and type) existing Lua modules if needed.
Teal only type checks when run from the command line though, which isn't the best when you want to embed Lua. At least thats what my reading of the docs says, I'd be happy if I'm wrong. But reading the docs now, it doesn't seem to say that any more - maybe its changed recently?
Edit: Oh yes it's still like that 'When loading and running the Teal module from Lua, there is no type checking! Type checking will only happen when you run tl check or load a program with tl run.' from
https://github.com/teal-language/tl/blob/master/docs/tutoria...
I haven't, but I might have to do a lot of work to get it working, as my typical use of Lua is deeply embedded and customized, and doesn't allow any filesystem access. I will definitely look into that, though, thank you. The only real Lua dialect I'm familiar with in that area is Moonscript.
Terra and Nelua are both very different in goals than Teal. Teal is literally gradual types integrated into Lua keeping as many of Lua's idioms as possible (to a fault[1]). Terra and Nelua are both very metaprogrammable systems programming languages. Nelua's goals are primarily to soften C's rough edges, comparable to something like Nim.
There's another one you missed in Pallene[2]. But again, it's goal was to optimize the stack sharing involved in using the C API. It also adds types though and maintains Lua idioms as much as possible.
