Grey Hack

Grey Hack is a massively multiplayer hacking simulator where the world is a vast network of procedurally generated computers, the terminal commands are modeled on real UNIX, and your actions persist whether you're online or not.

The game ships with File Explorer, Terminal, and Text Editor from the start, with additional utilities to install as you grow your skills. Targets vary in size, security, and exploit surface — any approach you've heard of in real-world hacking has some analogue here, from social engineering to scanning for admin flaws to chaining exploits.

The scripting language is exposed to players. Every terminal command and exploit is itself written in the game's scripting environment, so you can modify any existing tool or write your own. The same applies to exploits: when the canned ones don't cover your target, you write what you need.

The persistent world is the social layer. Changes you make to other people's computers stay there for the next player who connects. You can publish web pages, form guilds, run commissions, and attack other players. Single-player offline mode is available for those who want isolation from the always-online world. Currently in Alpha (0.8) with an open roadmap on the developer's forums.