Extreme Programming

Extreme Programming (XP) is a method or approach to software engineering and the most popular of several agile software development methodologies. It was formulated by Kent Beck, Ward Cunningham, and Ron Jeffries. Kent Beck wrote the first book on the topic, Extreme programming explained: Embrace change, published in 1999. The second edition of the book, which appeared in 2005, delves more into the philosophy of Extreme Programming and describes it as being:

History

Context

The 1990s had seen the great promise of object technologies launch ambitious projects that in many cases ended in failure. Objects themselves, while conferring numerous advantages of reuse, were not the panacea that many had hoped they would be. Fluid, rapidly-changing requirements demanded shorter lifecycles, and did not go well with more traditional methods of development, which usually required extensive design up front and penalized later design changes with higher costs or missed milestones.

Related Topics:
1990s - Object technologies - Panacea

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Origins

The Chrysler Comprehensive Compensation project was started in order to determine the best way to use object technologies, using the payroll systems at Chrysler as the object of research, with Smalltalk as the language and GemStone as the persistence layer. They brought in Kent Beck, a prominent Smalltalk practitioner, to do performance tuning on the system, but his role expanded as he noted several issues they were having with their development process. He took this opportunity to propose and implement some changes in their practices based on his work with his frequent collaborator, Ward Cunningham.

Related Topics:
Smalltalk - GemStone - Kent Beck - Performance tuning - Ward Cunningham

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:The first time I was asked to lead a team, I asked them to do a little bit of the things I thought were sensible, like testing and reviews. The second time there was a lot more on the line. I thought, "Damn the torpedoes, at least this will make a good article," asked the team to crank up all the knobs to 10 on the things I thought were essential and leave out everything else. —Kent Beck

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Beck invited Ron Jeffries to the project to help develop and refine these methods. Jeffries thereafter acted as a kind of coach to instill the practices as habits in the C3 team.

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Information about the principles and practices behind XP was disseminated to the wider world through discussions on the original WikiWiki, Cunningham's Portland Pattern Repository. Various contributors dissected and expanded upon the ideas, some becoming fervent advocates, others becoming critics, and yet others picking out ideas (see agile software development).

Related Topics:
WikiWiki - Portland Pattern Repository - Agile software development

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Current State

Beck edited a series of books on XP, beginning with his own Extreme Programming Explained, spreading his ideas to a much larger yet very receptive audience. Authors in the series went through various aspects attending XP and its practices, even a book critical of the practices.

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XP created quite a buzz in the late nineties and early two thousands, seeing adoption in a number of different milieus and environments radically different from its origins.

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Future Directions

The high discipline required by the original practices often went by the wayside, causing certain practices to be deprecated or left undone on individual sites. Agile development practices have not stood still, and XP is still evolving, assimilating more lessons from experiences in the field. In the second edition of Extreme Programming Explained, Beck added more values and practices, and differentiated between primary and corollary practices.

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