I’ve always been bothered by the dismissal of XP as just being “Scrum with tech practices.” But the differences between the two are much greater. First, while XP and Scrum both have related values, the practices of XP are mostly centered around sw development practices (such as paired programming), while Scrum is mostly about non-domain specific team practices. Second, XP includes Acceptance Test-Driven Development (ATDD). ATDD, which is a collaboration between the Product Owner, dev, and tester and which includes neither design nor coding and is therefore, not a technical practice. In other words, XP’s defined both about actually doing the work (Agile analysis, design, code and test) while creating a “container” or framework for developing software while Scrum is defined as a framework for doing any type of dev work, software or not. This results in XP learning both framework & software development practices from the beginning while Scrum adopters learn the framework and & then (hopefully) fill in the needed practices. I would suggest that this delay in learning ATDD is the biggest reason people have troubles with Scrum. This is more important than ever because as scale increases, ATDD is even more necessary.