This package provides interaction with an OCaml utop toplevel (REPL). utop.el has two components - a nice OCaml REPL with auto-completion and a minor mode (`utop-minor-mode'), which extends OCaml major modes (e.g. `caml-mode' and `tuareg-mode') with commands to evaluate forms directly in the REPL. See the "Integration with Emacs" section of the README for more info.