The Agile Manifesto (Agile Alliance, 2001a) merely describes the philosophies behind agile software development, it doesn t define the software process itself. The most famous, or infamous, depending on your point of view, agile software process is Kent Beck s (2000) Extreme Programming (XP) methodology, a process described by Warren Keuffel in his article aptly titled Extreme Programming. XP encourages programmers to select the most important features and developing them to completion within a short time frame. A team begins by putting together a collection of desirable features, as defined by the customer, each of which consists of a user story described on one index card. User stories are not detailed documentation, rather they are merely a reminder to have a conversation with your users to obtain detailed requirements. An XP team proceeds to iterate through an analysis-design-implementation-test cycle for each story, frequently producing a new release perhaps daily, perhaps monthly. XP requires intensive customer involvement; ideally, a customer is assigned to full-time participation with the team. Testing is a core activity in XP, not an afterthought, and test cases are actually developed before any real coding begins (an approach often called test-first design). XP also requires that developers work in pairs, addressing the common inability of programmers to write their own tests and dramatically improving productivity along the way (two heads working together are better than two heads working separately). XP advocates multiple builds per day, each of which is followed by automatically...