How the Cathedral Embraced the Bazaar, and the Bazaar Became a Cathedral.

Over the past 20 years, open source has become a widely adopted approach to develop software. Code repositories provide software to power cars, phones, and other things that are considered proprietary. In parallel, proprietary development has evolved from rigid, centralized waterfall approaches to agile, iterative development. In this paper, we share our experiences regarding this co-evolution of open and closed source from the viewpoints of tools, practices, and organizing the development work, concluding that today’s bazaars and cathedrals have much more common characteristics than those that separate them.