The OpenStack community prides itself on its "Four Opens": open source, open design, open development and open community. Each of the four opens has an impact on the choices made by the community and helps to shape the guiding principles and the shared culture of the community as well as its technical governance model.

In this short talk, I will present how the OpenStack community implemented its four opens; I will detail the implications in terms of governance, infrastructure, development processes and communication tools, and how similar approaches could be easily used by other communities.