Summary

XP is a lightweight methodology that focuses on coding as the main task. XP is based on four values: communication, simplicity, feedback, and courage. Communication is facilitated through pair programming, task estimation, iteration planning, and more. Simplicity means avoiding making things overly complicated and insisting that the basics be addressed first and foremost. Feedback is given by way of testing, customer stories, small iterations/frequent deliveries, pair programming/constant code reviews, and so on. Courage means the courage to do what is right whether you have to refactor a working system, throw code away, cancel a project, or insist on quality.

XP is based on five principles: rapid feedback, assuming simplicity, making incremental changes, embracing change, and doing quality work. In his landmark book on XP, Beck iterated four basic practices: coding, testing, listening, and designing. These practices are expressed further in 12 major areas of practice: the planning game, small releases, simple design, (automated) testing, continuous integration, refactoring, pair programming, collective ownership, a 40- hour week, an on-site customer, metaphor, and adherence to a coding standard. This book focus on two practices of XP: automated testing and continuous integration.