Here's a couple more that I've found useful over the years:

- pandoc: convert (almost) any document format to (almost) any other document format

- The Elm Compiler: Possibly the most widely used statically typed pure frontend language

- XMonad: A tiling window manager for linux that I enjoyed using even without knowing much Haskell

- Purescript: the other widely-used (for an FP language) statically typed pure compile-to-javascript language