  In this chapter we review some aspects of X-ray binaries, particularly those
presenting steady jets, i.e. microquasars. Because of their proximity and
similarities with active galactic nuclei (AGN), galactic jet sources are unique
laboratories to test astrophysical theories of a universal scope. Due to recent
observational progress made with the new generation of gamma-ray imaging
atmospheric Cherenkov telescopes and in view of the upcoming km3-size neutrino
detectors, we focus especially on the possible high-energy gamma radiation and
neutrino emission. In connection with this, we also comment about astrophysical
jets present in young stellar objects, and we briefly discuss similarities and
differences with extragalactic AGN and gamma-ray bursters.
