Building telecommunication network infrastructures is a key issue both, in developing regions and isolated areas in order to facilitate people not only access to information and new technologies, but also to give them the opportunity of self-organize. Nevertheless, despite the huge importance of the network infrastructure for the development of people, building a neutral and open communication system is not a priority for governments, so community networks are a solid and real alternative.In this document we present guifi.net, a bottom-up community network, born in Spain, having over 30,000 active nodes, totaling more than 55,000 km in network links, and showing a sustained growing rate.guifi.net is an opportunity to build a distributed telecommunications infrastructure governed by the participants in an indiscriminate way.But a network such as guifi.net is not only of interest in developing areas. In many countries, internet connections, despite being a basic service, are usually monopolized by a small number of private companies. An open and free network as guifi.net offers users the opportunity of being participants in the decisions regarding infrastructure and services.