The founding text of extreme-programming, published in 1999 by kent-beck — two years before the agile-manifesto. This first edition laid out XP as a "non-negotiable set of rules": either you did all of it or you weren't doing XP. kent-beck described it as a methodology for small teams developing software under changing requirements, with a specific list of practices that had to be adopted together because they supported one another.
Core structure (first edition)
The first edition organized XP around four values — communication, simplicity, feedback, courage — and approximately twelve to fifteen practices, presented as an integrated whole. Key practices included:
The "non-negotiable" stance was deliberate. kent-beck argued that the practices formed a system: if you removed the on-site customer, the planning game broke down; if you removed collective ownership, refactoring became politically difficult. The first edition presented this as all-or-nothing by design.
Relationship to the manifesto
The first edition predates snowbird-meeting-2001 by two years. XP was the most elaborated of the lightweight methodologies at the time, and kent-beck's book was the primary reason XP proponents had a large presence at Snowbird. The manifesto's values — particularly individuals-and-interactions and working-software — reflect XP's emphasis directly.
Reception
The first edition was widely read and widely controversial. Critics argued XP was too prescriptive and made unrealistic demands (on-site customer; 40-hour weeks). Practitioners found it energizing precisely because it was prescriptive — unlike heavyweight methodologies, at least you knew what you were supposed to do.
The second edition (xp-explained-second-edition, 2004) significantly revised the approach, making it less prescriptive and expanding scope to larger teams.