[en] The possibility to create a tunable gamma-ray source using two different approaches has been investigated. The first source relies on crystal diffraction and uses bremsstrahlung produced by electrons from the 15 MeV linear accelerator of the university of Ghent. It delivers very well defined monochromatic gamma-ray beams with energies between 80 and 1000 keV. The second approach uses Compton scattering of gamma-rays with a poorer energy resolution but a higher intensity. Some applications of these sources are described. (author)