Abstract
This opinion piece discusses the Bioconductor project for open-source bioinformatics and the engineering concepts underlying its effectiveness to date. Since the inception of Bioconductor in 2002 with 15 software packages devoted to analysis of DNA microarrays, it has grown into an ecosystem of ∼3,000 packages contributed by more than 1,000 developers. Aspects of the history and commitments are reviewed here to contribute to thinking about the design and orchestration of future open-source software projects.