User shell with text-mode full-screen interface.
GNU Midnight Commander is a visual file manager, licensed under GNU General Public License and therefore qualifies as Free Software. It's a feature rich full-screen text mode application that allows you to copy, move and delete files and whole directory trees, search for files and run commands in the subshell. Internal viewer and editor are included.
Midnight Commander is based on versatile text interfaces, such as Ncurses or S-Lang, which allows it to work on a regular console, inside an X Window terminal, over SSH connections and all kinds of remote shells.
Port icon has the following license: GNU GPLv3 https://choosealicense.com/licenses/gpl-3.0/ (c) Midnight Commander