Coalton is an efficient, statically typed Lisp with ideas from Haskell and OCaml | Hacker News

Coalton is presented as a statically typed Lisp for Common Lisp users, blending functional programming ideas with the CL ecosystem.

A Hacker News comment said it can be learned separately from Common Lisp and mixed with existing CL code through the REPL.

Its type system supports domain-specific types and algebraic data types, making it useful for stronger modeling and safer code.

Because documentation is sparse, the comment recommends studying Haskell, OCaml, or F# examples as a guide.