libutop-ocaml-dev 1.19.3-2build1 (arm64 binary) in ubuntu bionic

 utop is an improved toplevel for OCaml. It can run in a terminal or
 in Emacs. It supports line edition, history, real-time and context
 sensitive completion, colors, and more.
 .
 This package contains the development stuff needed to use the
 utop library in your programs.