The “Open Conference System”, OCS, is an open source, free, web publishing tool which helps in planning, organizing and managing a conference. It allowed us to experience the benefits of two important trends today: sharing knowledge and open source. ElPub2003 as well as this years’ ElPub2004 have been managed through this software. OCS allows the creation of a conference web site, editing and disseminating calls for papers, submission of abstracts and full papers, manage the reviewing process, and help with the registration process. The use of the Open Archives Initiative (OAI) standards of metadata makes possible the indexation and search of the conference papers, which are incorporated to a universal library of databases for scholarly and public use.