Extreme Programming (XP) is a new method in or approach to software engineering, formulated by Kent Beck, who wrote the first book on the topic, "Extreme Programming Explained. Embrace Change" (ISBN 0201616416).
For more information on this and related topics, see the definition at Ward Cunningham's website, http://www.c2.com/cgi/wiki?ExtremeProgramming
Fundamental for the method are:
- short incremental programming steps
- continuous, often repeated automated regression testing. See JUnit.
- pair programming
- user interaction in the programming team
- fixing all known bugs before adding functionality
- refactoring
The following text needs to be merged:
Extreme programming, or "XP" takes certain simple practices that are known to improve software quality. Then, it takes these to logical extremes.
1. Requirements are addressed by having a customer on-site, available to the programmers. If this is not possible, the customer may describe use cases on cards, that are periodically photocopied for the engineering staff.
2. Simple code is more likely to work. Therefore, extreme programmers only write code to meet actual needs in the present project.
3. Code reviews are good. Therefore XP has programmers program in pairs, sharing one screen and keyboard.
4. Testing code is good. Therefore, in XP, test suites are written before the code is written. The code is considered complete when it passes the tests. The system is periodically, or immediately tested using all preexisting automated tests to assure that it works.
Reference:
- Kent Beck, Extreme programming explained, Addison Wesley, 2000
Controversial aspects:
Detailed specifications are not written.
A customer representative is attached to the project.