This guide (developed in the context of the FLOSSMETRICS and OpenTTT projects) present a set of guidelines and suggestions for the adoption of open source software within SMEs, using a ladder model that will guide companies from the initial selection and adoption of FLOSS within the IT infrastructure up to the creation of suitable business models based on open source software.

The guide is split into an introduction to FLOSS and a catalog of open source applications, selected to fulfill the requests that were gathered in the interviews and audit in the OpenTTT project. The application areas are infrastructural software (ranging from network and system management to security), ERP and CRM applications, groupware, document management, content management systems (CMS), VoIP, graphics/CAD/GIS systems, desktop applications, engineering and manufacturing, vertical business applications and eLearning.

This is the third edition of the guide; the guide is distributed under a CC-attribution-sharealike 3.0 license. The author is Carlo Daffara (cdaffara@conecta.it).