The EU 7FP project Micro B3 (Biodiversity, Bioinformatics, Biotechnology) will develop innovative bioinformatic approaches and a legal framework to make large-scale data on marine viral, bacterial, archaeal and protists genomes and metagenomes accessible for marine ecosystems biology and to define new targets for biotechnological applications. Micro B3 will build upon a highly interdisciplinary consortium of 32 academic and industrial partners comprising world-leading experts in bioinformatics, computer science, biology, ecology, oceanography, bioprospecting and biotechnology, as well as legal aspects. Micro B3 is based on a strong user- and data basis from ongoing European sampling campaigns to long-term ecological research sites.