This open access book constitutes the proceedings of the 24th International Conference on Agile Software Development, XP 2023, which took place in Amsterdam, The Netherlands, during June 13-16, 2023. 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 “Whole Team Sustainability”. The 11 full papers and 1 short paper presented in this volume were carefully reviewed and selected from 40 submissions. They focus on agile practices and agile in the large.

This open access book constitutes the proceedings of the 19th International Conference on Agile Software Development, XP 2018, held in Porto, Portugal, in May 2018. XP is the premier agile software development conference combining research and practice, and XP 2018 provided a playful and informal environment to learn and trigger discussions around its main theme - make, inspect, adapt. The 21 papers presented in this volume were carefully reviewed and selected from 62 submissions. They were organized in topical sections named: agile requirements; agile testing; agile transformation; scaling agile; human-centric agile; and continuous experimentation.