Portuguese research environment has been changing and growing significantly in these almost two decades; it was very small and underdeveloped until the 1990’s. The number of researchers and the scientific output referenced internationally has been growing in the last years at an annual average rate higher than 10%. Considering the size and significance of their research output, as well their legal status, the Higher Education Institutions (HEI), i.e. Universities, the Polytechnics, the Higher Institutes and the Research Centres (RC) constitute the Portuguese core of the public research system. Other sorts of institutions also carry out scientific research in Portugal, but to a much smaller extent, such as public and private hospitals, institutes, private companies, etc. The HEIs carry out the most significant proportion of the scientific output produced in Portugal.