When I first learned eXtreme Programming (XP), my mentors introduced it using four circles.  I really liked how the four circles made it easy to remember the XP practices, and I liked how it made them easier to remember.  This post is a walkthrough of the four circles of XP.

The Four Circles of XP
The four circles of XP:

• Coding Circle
• Team Circle
• Process Circle
• Product Circle

The four circles group the XP practices in a simple way:

• Coding Circle - Pair Programming, Refactoring, Testing
• Team Circle - Coding Standards, Collective Ownership, Continuous Integration
• Process Circle - 40-hour Week, Metaphor, Simple Design, Short Releases
• Product Circle - On-site Customer, Planning Game

For an explanation of the XP practices see XP Practices (Wikipedia).

The Four Circles of XP at a Glance
Here is a view of the XP practices at a glance:

The Coding Circle
The Coding Circle includes Pair-Programming, Refactoring, and Testing.  Here is a view of the Coding Circle highlighted:

The Team Circle
The Team Circle includes Coding Standards, Collective Ownership, and Continuous Integration.  Here is a view of the Team Circle highlighted:

The Process Circle
The Process Circle includes 40-Hour Week, Metaphor, Short Releases, and Simple Design.  Here is a view of the Process Circle highlighted:

The Product Circle
The Product Circle includes Planning and On-Site Customer.  Here is a view of the Product Circle highlighted: