Tests from a Hat (Sept. '10)
Movie Retrospective (Aug. '10)
Embracing Commitment (Dec. '09)
Alexey Krivitsky Interview (Dec. '09)
100 Impediments (Aug., '09)
Summary Sheet: Twenty Ways to Split Stories (July, '09)
User Story Examples (April, '09)
Declan Whelan Interview (March, '09)
Lisamarie Babik Interview (March, '09)
A Gallery of Team Rooms and Charts (updated Feb, '09)

Overview of XP

Review: Extreme Programming Explained, 2/e
Extreme Programming as Nested Conversations (in Methods and Tools)
Metaphors for Extreme Programming (speech at XP '02)
Introduction to Extreme Programming
Introduction to XP (.PPT, Feb., 2000)
XP and its Values
XP on One Page (mini-poster)

Other Agile Processes

Review: The Knowledge-Creating Company
Scrum on a Page

Programming - Test-First

Tests from a Hat
Sudoku Solver (TDD)
Sufficient Completeness and Testing
A Comparison Algorithm for TDD
Cutting with the Grain (with Kent Beck and Joseph Leddy)
The Test-First Stoplight (English, Spanish)
The Test/Code Cycle in XP: Part 1, Model (Former title: "A Bibliographic System Developed Using JUnit") [*] (Original/English/Java, English/C#, English/Delphi, Japanese/Java)
The Test/Code Cycle in XP: Part 2, GUI (Former title: "Using JUnit to Unit-Test GUIs"). Published as a chapter ("A Java Example") in Extreme Programming Installed, by Ron Jeffries et al. (Original/English/Java, Japanese/Java)
Test-First Challenge

Programming - Refactoring

Refactoring in Ruby - InformIT interview with Bill Wake and Kevin Rutherford
Refactoring Demo Screencast
Refactoring Grid
Refactoring Presentation (Feb., 2000)
Refactoring: An Example [*]
Refactoring: An Example, Extended
Refactorings from Writing Efficient Programs
From 0 to Composite (and Back Again)
Command, Interpreter, Visitor
The Impact of Refactoring on Tests (Originally published at, January, 2004)

Books at

Refactoring Workbook (for Java)
Refactoring in Ruby

Customer / Product Owner - General

User Story Examples
Slicing Functionality: Alternate Paths
Twenty Ways to Split Stories
Summary Sheet: Twenty Ways to Split Stories
Customer Value: Unbundling
Customer Value: Short-Term and Long-Term
How to Be a Customer of XP Software [*]

Customer / Product Owner - Testing

Semantics of Fit: A Path Toward New Tools
Procedural and Declarative Tests
Acceptance Tests for a Query System
Acceptance Test Mechanisms
A Fit Spreadsheet


XPlorations is a series of articles describing various aspects of XP. Several articles appear in two books: Extreme Programming Explored, by Bill Wake (many XPlorations), and Extreme Programming Installed, by Ron Jeffries et al. (the GUI test article).

Want the source code for the examples? Download a zip file.

Subscribe to XPlorations
An announcement-only list for XP articles


Configuration Management on a Page
Ratchets Capture Progress: Steps to Continuous Integration
Continuous Integration in XP
Java Coding Standard on a Page
The System Metaphor [*]
Programming in Pairs - Some Scenarios [*]
Where's the Architecture? [*]
How do you do a performance spike?
Reactions: Code Ownership, Integration, Workspace, Release Schedule, and Coding Standards [*]


ISO Certification for XP at LogicaCMG
INVEST in Good Stories, and SMART Tasks
Agile Project Management, XP Style
Story Time: Release Planning [*]
Distortions in Velocity
Simplified Iteration Planning
An Iteration Planning Game [*]
XP Programmer's Cube - A Day in the Life [* (except cube)] Free XP Programmer's Cube! Send me your physical address, and I'll send you a cube. I don't keep your physical or email address on file; this is just my "thank-you" gift to the community.


Set-Based Concurrent Engineering
Subjunctive Programming
Ten Things XP Teams Say
Introduction to Extreme Programming
Programming as a Performance Art
Managing XP: Manager, Tracker, Coach [*]
How to Be a Customer of XP Software [*]
Economics of XP
Lean and Software


Movie Retrospective
Alexey Krivitsky Interview
Embracing Commitment
100 Impediments
Declan Whelan Interview
Lisamarie Babik Interview
Patterns for Iteration Retrospectives
What's in Your Team Room?
A Gallery of Team Rooms and Charts
Books for Coaches
Coaching: Drills and Exercises
Managing XP: Manager, Tracker, Coach [*]
The Humble Yo
XP Radar Chart
Coaching Charts Exercise


The Test/Code Cycle in XP

The Test-First Stoplight

  • Spanish. Courtesy of Diego Santa.


[*] - in Extreme Programming Explored

Copyright 1994-2010, William C. Wake -