A pretend Debian machine that runs entirely in this tab. Type real commands, finish 22 short quests, and build the muscle memory before you touch a real server. Nothing to install, nothing to break, nothing sent anywhere.
How this works. The folders outside your home (/etc, /usr, /bin) are copied from a real Debian install,
the way security researchers build convincing fake machines: real names, real permissions, and real contents for a
few files. Your home folder is yours to wreck. Type reset or press Start over to get a fresh machine.
Learning it first? The quests follow Part 1: The Command Line, From Zero and Part 2: Streams & Pipes. When you finish, try a real server at OverTheWire: Bandit.
What it can’t do. There is no network, no sudo, no text editor and no installing software here. Those
need a real machine, and the guides show you how.