XP and OpenSource Dierk König Canoo Engineering AG Kirschgartenstr.7 CH-4051 Basel Switzerland mailto:dierk.koenig@canoo.com XP seems to be impossible to apply to the OpenSource Community, for the typical szenario does not allow Pair Programming, shared planning, Customer On-Site and the like. On the other hand some XP practices make a lot of sense for OpenSource: Unit Tests, Acceptance Tests, Continuous Integration, Refactoring. The Collective Code Ownership is even the foundation of OpenSource. I would like to contribute my experiences with OpenSource and XP that I gathered when bringing up the Canoo WebTest package. Beside the experiences made with tools to support the process, most of the experience concerns group behaviour like: - make users provide feedback - make feature requesters provide acceptance tests - make contributors provide tests and conform to the Coding Standard.