Accountability. Transparency. Responsibility. These are not words that are often applied to software development. In this completely revised introduction to Extreme Programming (XP), Kent Beck describes how to improve your software development by integrating these highly desirable concepts into your daily development process. The first edition of Extreme Programming Explained is a classic. It won awards for its then-radical ideas for improving small-team development, such as having developers write automated tests for their own code and having the whole team plan weekly. Much has changed in five years. This completely rewritten second edition expands the scope of XP to teams of any size by suggesting a program of continuous improvement based on.

This open access book constitutes the proceedings of the 22nd International Conference on Agile Software Development, XP 2021, which was held virtually during June 14-18, 2021. XP is the premier agile software development conference combining research and practice. It is a unique forum where agile researchers, practitioners, thought leaders, coaches, and trainers get together to present and discuss their most recent innovations, research results, experiences, concerns, challenges, and trends. XP conferences provide an informal environment to learn and trigger discussions and welcome both people new to agile and seasoned agile practitioners. This year’s conference was held with the theme “Agile Turns Twenty While the World Goes Online”. The 11 full and 2 short papers presented in this volume were carefully reviewed and selected from 38 submissions. They were organized in topical sections named: agile practices; process assessment; large-scale agile; and short contributions.

This open access book constitutes the proceedings of the 21st International Conference on Agile Software Development, XP 2020, which was planned to be held during June 8-12, 2020, at the IT University of Copenhagen, Denmark. However, due to the COVID-19 pandemic the conference was postponed until an undetermined date. XP is the premier agile software development conference combining research and practice. It is a hybrid forum where agile researchers, academics, practitioners, thought leaders, coaches, and trainers get together to present and discuss their most recent innovations, research results, experiences, concerns, challenges, and trends. Following this history, for both researchers and seasoned practitioners XP 2020 provided an informal environment to network, share, and discover trends in Agile for the next 20 years. The 14 full and 2 short papers presented in this volume were carefully reviewed and selected from 37 submissions. They were organized in topical sections named: agile adoption; agile practices; large-scale agile; the business of agile; and agile and testing.

Without careful ongoing planning, the software development process can fall apart. Extreme Programming (XP) is a new programming discipline, or methodology, that is geared toward the way that the vast majority of software development projects are handled -- in small teams. In this new book, noted software engineers Kent Beck and Martin Fowler show the reader how to properly plan a software development project with XP in mind. The authors lay out a proven strategy that forces the reader to plan as their software project unfolds, and therefore avoid many of the nasty problems that can potentially spring up along the way.

The first book to cover Agile Modeling, a new modeling technique created specifically for XP projects eXtreme Programming (XP) has created a buzz in the software development community-much like Design Patterns did several years ago. Although XP presents a methodology for faster software development, many developers find that XP does not allow for modeling time, which is critical to ensure that a project meets its proposed requirements. They have also found that standard modeling techniques that use the Unified Modeling Language (UML) often do not work with this methodology. In this innovative book, Software Development columnist Scott Ambler presents Agile Modeling (AM)-a technique that he created for modeling XP projects using pieces of the UML and Rational's Unified Process (RUP). Ambler clearly explains AM, and shows readers how to incorporate AM, UML, and RUP into their development projects with the help of numerous case studies integrated throughout the book. AM was created by the author for modeling XP projects-an element lacking in the original XP design The XP community and its creator have embraced AM, which should give this book strong market acceptance Companion Web site at www.agilemodeling.com features updates, links to XP and AM resources, and ongoing case studies about agile modeling.

Software development is being revolutionized. The heavy-weight processes of the 1980s and 1990s are being replaced by light-weight, so called agile processes. Agile processes move the focus of software development back to what really matters: running software. This is only made possible by accepting that software developmentisacreativejobdoneby,with,andforindividualhumanbeings.For this reason, agile software development encourages interaction, communication, and fun. This was the focus of the Fifth International Conference on Extreme P- grammingandAgileProcessesinSoftwareEngineeringwhichtookplacebetween June 6 and June 10, 2004 at the conference center in Garmisch-Partenkirchen at the foot of the Bavarian Alps near Munich, Germany. In this way the conference provided a unique forum for industry and academic professionals to discuss their needs and ideas for incorporating Extreme Programming and Agile Metho- logies into their professional life under consideration of the human factor. We celebrated this year’s conference by re?ecting on what we had achieved in the last half decade and we also focused on the challenges we will face in the near future.

This book is open access under a CC BY license. The volume constitutes the proceedings of the 18th International Conference on Agile Software Development, XP 2017, held in Cologne, Germany, in May 2017. The 14 full and 6 short papers presented in this volume were carefully reviewed and selected from 46 submissions. They were organized in topical sections named: improving agile processes; agile in organization; and safety critical software. In addition, the volume contains 3 doctoral symposium papers (from 4 papers submitted).