A key objective of the Professionals and Citizen Network for Integrated Care (PICNIC) project was to provide products for a European and potentially worldwide software market. The approach followed was through the delivery of a number of Open Source (OS) components, to be integrated into applications that deliver similar services across the participating regions, aiming at their exploitation by other regions and the industry. This chapter describes the technology developed during the lifecycle of the PICNIC project, focusing on the three core services of Clinical Messaging, Access to Patient Data, and Collaboration. For each service, the entire process of how to turn its functional specifications into reusable components and common data sets in order to support Information Technology (IT) services for the next generation of secure, user-friendly healthcare networks is presented by means of common documentation tools. Security and privacy issues are also addressed.