PLANETHPC is Framework 7 Support Action designed to bring together the HPC community in Europe and beyond to exchange knowledge, to identify shared and complementary goals and to identify the research challenges ahead. This will culminate in the production of a research roadmap which outlines research priorities for the mid to long term.The project involves establishing a free-to-join network of members (PLANET), and providing facilities enabling them to share knowledge. These will include providing an on-line forum for exchange of ideas, establishing special interest groups, organising events such as workshops for knowledge exchange and publicising the network. Members of the network will gain value via interactions with other members and through support activities such as newsletters and opportunities to contribute to the recommendations that the project will make in the research roadmap The project will be carried out by a single partner, EPCC, the supercomputing centre at The University of Edinburgh, for reasons of efficiency and simplicity. The activities of the project will be overseen by an invited expert group.