opam - OCaml Package Manager
OPAM is a source-based package manager for OCaml. It supports
multiple simultaneous compiler installations, flexible package
constraints, and a Git-friendly development workflow.
Managing your OCaml installation can be as simple as:
opam list -a # List the available packages
opam install lwt # Install LWT
opam update # Update the package list
...
opam upgrade # Upgrade installed packages to their latest version
It has to be initialised. To do it, you can use the following command:
opam init
It is not recommended to run opam as root.
Apparently it rather installs per-user packages.