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 book contains the refereed proceedings of the 16th International Conference on Agile Software Development, XP 2015, held in Helsinki, Finland, in May 2015. While agile development has already become mainstream in industry, this field is still constantly evolving and continues to spur an enormous interest both in industry and academia. The XP conference series has always played, and continues to play, an important role in connecting the academic and practitioner communities, providing a forum for both formal and informal sharing and development of ideas, experiences, and opinions. The theme of XP 2015 "Delivering Value: Moving from Cyclic to Continuous Value Delivery" reflects the modern trend towards organizations that are simultaneously very efficient and flexible in software development and delivery. The 15 full and 7 short papers accepted for XP 2015 were selected from 44 submissions. All of the submitted papers went through a rigorous peer-review process. Additionally, 11 experience reports were selected from 45 proposals, and in each case the authors were shepherded by an experienced researcher.

This book contains the refereed proceedings of the 4th International Conference on Software Business (ICSOB) held in Paphos, Cyprus, in June 2014. The theme of the event was "Shortening the Time-to-Market-From Short Cycle Times to Continuous Value Delivery."

The 18 full papers, two short papers, two industrial papers and two doctoral consortium abstracts accepted for ICSOB were selected from 45 submissions and are organized in sections on: strategic aspects, start ups and software business, products and service business, software development, ecosystems and platforms and enterprises.