Communication . Software development is a team effort. Effective teams must communicate well. XP focuses on open , effective communications.
Simplicity . In XP, it is better to do a simple thing now, and tomorrow pay a little more if a more complex solution is needed.
Feedback . Feedback goes hand-in-hand with communication. When you communicate, or perform some action, the sooner you receive effective feedback, the more effective you are. XP promotes rapid feedback.
Courage . To use XP, the team must have the courage to do the right thing, even when there is pressure to do otherwise . You must have courage to throw away code when such actions are warranted. You must have the courage to take appropriate risks and the courage to admit when you have gone into a blind alley and need to back up.
