What Is Extreme Programming?

Extreme programming (XP) is a software development methodology pioneered by Kent Beck in the late 1990s. In contrast to other methodologies, which tend to emphasise a large-scale design effort at the beginning of a programming project, XP suggests moving in incremental steps, and writing flexible code which can be easily adapted if the customer requests functional changes during the course of the project.

Distinctive aspects of the XP approach include :-

Strong emphasis on testing. Automated unit tests are written so that programmers can easily verify that no new bugs have been introduced to the code base.

Pair programming – programmers work in pairs, with one constantly critiquing the work of the other. This is intended to provide the equivalent of an ongoing code review.

Continuous Integration – a build is performed and tested at least once a day. This is to prevent code problems from accumulating in secret.

Re-factoring – taking time-outs from introducing new features to improve the design of existing code, making it easier to change in future.