All over the world, public research organizations (PRO) have adopted a policy of systematic patenting over their research results. Economic consequences of this change have been widely documented. Yet, less has been written on the way PRO use their intellectual property. We show here that, although firms have for long understood the importance of a contextualized use of their patent portfolios, it is not the case of PRO, which remain locked into a restrictive view of patents based on exclusivity. But a policy of exclusive licensing is not the only option for PRO. In some cases, that we attempt to define, it is more efficient in order to foster technology transfer, to adopt more open model of use, based on non-exclusive licenses or on open source strategies.