  The energy domain between 10 MeV and hundreds of GeV is an essential one for
the multifrequency study of extreme astrophysical sources. The understanding of
spectra of detected gamma rays is necessary for developing models for
acceleration, emission, absorption and propagation of very high energy
particles at their sources and in space. After the end of EGRET on board the
Compton Gamma Ray Observatory this energy region is not covered by any other
experiment, at least up to 50 GeV where ground Cerenkov telescopes are
beginning to take data. Here we will review the status of the space experiment
GLAST that will fill this energy region from March 2006 with particular
emphasis at the connection with all the other ground and space planned
experiments and at the contribution of GLAST to particle physics.
