It’s a fine line between chatting and pair programming by Pascal Van Cauwenberghe
A short story about a pair programming episode. It can be hard to see the difference between two programmers chatting or pair programming, if you don’t look closely. You don’t have to look closely, you have to look at the result.

Agile Fixed Price Projects by Pascal Van Cauwenberghe

A two-part article that describes how you can introduce agile techniques into “fixed price” contracts to increase your chances of success and customer happiness.

xpperspectives The XP Game explained, by Vera Peeters and Pascal Van Cauwenberghe
This chapter from Extreme Programming Perspectives explains more about the reasoning behind the different elements of the XP Game.

Refactoring or upfront design?, by Pascal Van Cauwenberghe
This chapter from Extreme Programming Perspectives is an update of the paper presented at XP 2001 conference.

Rock Climbing and Extreme Programming by Ye Yongqing.
The author discovers that most of the ideas of extreme programming are quite suitable to rock climbing.

Simple design and unit testing with Enterprise Javabeans: the Box Metaphor by Vera Peeters. Presented at XP2001.
A metaphor to guide you in designing simple, consistent and testable EJB systems.

A great challenge: XP in a typical dot-com by Ye Yonqing and Winston Wolff. Presented at XP2001.
This paper describes the implementation of XP in a young, dynamic, growing global web bank and an environment with rapid changing user requirements.


The Systems Thinking wiki has a list of books on XP, Agile software development, teams, people, Theory of Constraints, Lean Thinking… Enough interesting material there to keep you occupied for years!