I think folks (especially agile skeptics) should take a close look at Feature-Driven Development (FDD) if for no other reason than because it is an example of an agile method that is very different from XP. FDD is quite agile while still employing of many of the traditional practices that agile skeptics are probably more accustomed to seeing.
For example, FDD has the more traditional progression of waterfall-ish phases in its iterations (while still being highly iterative and collaborative). FDD does conduct up-front planning, design and documentation and relies very heavily upon domain modeling. FDD also uses feature-teams with chief architects/programmers and traditional code-ownership and code-review (as opposed to pair-programming and refactoring).
To that end, here are some more resources about FDD so folks can learn more about it and become more aware of the fact that XP isnt the only agile "game" in town when it comes to development practices (SCRUM and DSDM are focused primairly on planning rather than development practices):
- Feature-Driven Development and Extreme Programming, by Stephen Palmer -- Superficial similarities between Feature-Driven Development (FDD) and Extreme Programming (XP) hide a number of very important differences between the two processes. This article provides a short comparison of FDD and XP.
- A brief article from me about how FDD is Football-Driven Development (and XP is Rugby)
- The Original description of FDD from Chapter 6 of Peter Coad's Java Modeling in Color with UML
- An exceprt from Stephen Palmer's and John M. (Mac) Felsing's book A Practical Guide to Feature-Driven Development describing FDD Best-Practices
- Jeff DeLuca's FDD website including the latest description of FDD processes and an FDD Overview presentation
- The FDD Portal
- Stephen Palmer's set of articles on FDD and articles on Color Modeling
- Peter Coad's descriptions of feature-sets and color modeling patterns including a color modeling overview, and Archetypes, Color, and the Domain-neutral Component
- David Anderson's Channel FDD articles (scroll to the far right-hand-side)
- the newly created colormodeling YahooGroup