Due to the increasingly fast technological advancement of the ICT world, 'hi-tech' industries feel a growing need to open to the external world of research and innovation. The usage of external innovation sources allows overcoming the limits of internal resources in terms of capacities, skills and creativity. With respect to the traditional concept of "Closed Innovation", that is the innovation constrained within the internal R&D departments, the "Open Innovation" paradigm leverages on tools that enable importing external resources, thus boosting the quality and quantity of innovative technological solutions. In this paper the basic concepts and the possible "Open Innovation" applications will be presented, starting from the introduction of the paradigm as invented by Henry William Chesbrough in 2003. Furthermore, methodologies and computer tools will be described that are widely adopted to apply the paradigm to industrial settings, as well as the possible barriers to its implementation. Lastly, given the importance of universities, research centers and other companies as external sources for Open Innovation, some pointers will be provided to the selection process of technology innovation partners.