FATE: hacking game
Some of you might be curious what it like to be a hacker.
Well, FATE is a game that can help you understanding concepts, principles and various techniques used in hacking.
FATE is terminal based and it does not have any graphics. It emulates UNIX shell pretty well. Plus FATE is extremely small size and has low resource consumption.
FATE is based on a number of levels/missions. You receive these missions by chatting on IRC channel (you have to telnet irc.area-6.net 6667 from the console) with your boss, m101, and his affiliates. Usually you have to hack into a server by using some sort of remote exploit, password decryptor or some other hacking technique. Your typical target would be a Linux machine vulnerable some way. In order to succeed in the game you have to be versatile with UNIX commands and understand principles of UNIX/Linux systems. If you get stuck try to study one of the tutorials: FATE Tutorials.
FATE is free and can be downloaded here.
P.S. By the way, FATE is only a game. Don't try the stuff done in the game for real. FBI or someone else might call you :-).