The field of software engineering is characterized by speed and turbulence in many regards. While new ideas are proposed almost on a yearly basis, very few of them live for a decade or a longer. Lightweight software development methods were a new idea in the latter part of the 1990s. Now, ten years later, they are better known as agile software development methods, and an active community driven by practitioners has formed around the new way of thinking. Agile software development is currently being embraced by the research community as well. As a sign of increased research activity, most research-oriented conferences have an agile software development track included in the conference program. The XP conference series established in 2000 was the first conference dedicated to agile processes in software engineering. The idea of the conference is to offer a unique setting for advancing the state of the art in research and practice of agile processes. This year's conference was the tenth consecutive edition of this international event. Due to the diverse nature of different activities during the conference, XP is claimed to be more of an experience rather then a regular conference. It offers several different ways to interact and strives to create a truly collaborative environment where new ideas and exciting findings can be presented and shared. This is clearly visible from this year's program as well.

"This book constitutes the refereed proceedings of the 10th International Conference on Agile Processes in Software Engineering and Extreme Programming, XP 2009, held in Sardinia, Italy, in May 2009.Out of 40 paper submissions 12 full papers were accepted for publication in this book together with 2 keynote papers, 11 short papers, 23 workshop and tutorial papers, 5 posters, 6 demonstrations and information on 3 panel discussions. The papers represent a set of high-quality research studies addressing a wide variety of different topics, ranging from very technical issues to human-related aspects of agile software development, including novel ideas on agile software research."

Keynote Papers.- What They Dont Teach You about Software at School: Be Smart!.- Keynote: Beyond Budgeting in a Lean and Agile World.- Research Papers.- Developing a Test Automation Framework for Agile Development and Testing.- Long-Term Effects of Test-Driven Development A Case Study.- Communicating Domain Knowledge in Executable Acceptance Test Driven Development.- An Empirical Study on the TDD Conformance of Novice and Expert Pair Programmers.- An Exploratory Study of Developers' Toolbox in an Agile Team.- Balancing Individual and Collaborative Work in Agile Teams.- Organizational Enablers for Agile Adoption: Learning from GameDevCo.- Migrating Defect Management from Waterfall to Agile Software Development in a Large-Scale Multi-site Organization: A Case Study.- Perceptive Agile Measurement: New Instruments for Quantitative Studies in the Pursuit of the Social-Psychological Effect of Agile Practices.- A Survey of Perceptions on Knowledge Management Schools in Agile and Traditional Software Development Environments.- Empowering Students and the Community through Agile Software Development Service-Learning.- Putting Agile Teamwork to the Test - An Preliminary Instrument for Empirically Assessing and Improving Agile Software Development.- Short Papers.- Agile Software Development and CMMI: What We Do Not Know about Dancing with Elephants.- Is ISO/IEC 15504 Applicable to Agile Methods?.- Lesson Learnt from an Agile Implementation Project.- A Study of Risk Management in DSDM.- A Storytest-Driven Approach to the Migration of Legacy Systems.- XP Practices: A Successful Tool for Increasing and Transferring Practical Knowledge in Short-Life Software Development Projects.- Distributed Agile Development: A Case Study of Customer Communication Challenges.- Customer and UserInvolvement in Agile Software Development.- Integration of Extreme Programming and User-Centered Design: Lessons Learned.- Optimizing Agile Processes by Early Identification of Hidden Requirements.- Negotiating Contracts for Agile Projects: A Practical Perspective.- Workshops and Tutorials.- The Lego Lean Game.- Agile Process Smells and Root Cause Analysis.- Agile in Large-Scale Development Workshop: Coaching, Transitioning and Practicing.- What Does an Agile Coach Do?.- Workshop - Mechanics of Good - Creating Well Functioning Distributed Teams.- Test-Driven User Interfaces.- The New New NEW! Product Development Game.- Positioning Agility.- Scrum Board Game.- XP2009 Workshop: Climbing the Dreyfus Ladder of Agile Practices.- Software "Best" Practices: Agile Deconstructed.- XP Workshop on Agile Product Line Engineering.- Test Driven Development: Performing Art.- Business Value Game.- Where Agile Research Meets Industry Needs: Starting from a 10-Year Retrospective.- Continuous Integration - How Do You Know That Your Application Still Works?.- Executable Requirements in Practice.- Product Owners Jamboree.- Explaining the Obvious - How Do You Teach Agile?.- Architecture-Centric Methods and Agile Approaches.- 3rd International Workshop on Designing Empirical Studies: Assessing the Effectiveness of Agile Methods (IWDES 2009).- Telling Your Stories: Why Stories Are Important for Your Team.- Elements of an Art - Agile Coaching.- Posters.- A Survey on Industrial Software Engineering.- Modeling Spontaneous Pair Programming When New Developers Join a Team.- Summary Reporting for a Linked Interaction Design-Scrum Approach: How Much Modeling Is Useful?.- Software Product Line Engineering Approach for Enhancing Agile Methodologies.- FLEXI Project Management Survey.-Demonstrations.- Documentation by Example.- Alaska Simulator - A Journey to Planning.- Using Metric Visualization and Sharing Tool to Drive Agile-Related Practices.- ActiveStory Enhanced: Low-Fidelity Prototyping and Wizard of Oz Usability Testing Tool.- FitClipse: A Tool for Executable Acceptance Test Driven Development.- Using Digital Tabletops to Support Distributed Agile Planning Meetings.- Additional Material: Panels.- The Future of Lean in an Agile World.- What Skills Do We Really Need in Agile Software Development? - Discussion of Industrial Impacts and Challenges.- Perspectives on Agile Coaching.