Kio

Kio is a statically typed, embeddable programming language designed for ultra-portability. It allows developers to write a package once and transpile it to multiple host languages including JavaScript, Python, Rust, Go, Swift, Haskell, and more. Kio produces idiomatic code for each host language without requiring a separate runtime. It features strong static typing, formal guarantees, user-defined operators, and library-defined control structures. Tooling includes fast typechecking, editor support, parallel builds, and a browser-based REPL.