Review on latest progress on Supergiant Fast X-ray Transients and future
  direction
  In the recent years, the discovery of a new class of Galactic transients with
fast and bright flaring X-ray activity, the Supergiant Fast X-ray Transients,
has completely changed our view and comprehension of massive X-ray binaries.
These objects display X-ray outbursts which are difficult to be explained in
the framework of standard theories for the accretion of matter onto compact
objects, and could represent a dominant population of X-ray binaries. I will
review their main observational properties (neutron star magnetic field,
orbital and spin period, long term behavior, duty cycle, quiescence and
outburst emission), which pose serious problems to the main mechanisms recently
proposed to explain their X-ray behavior. I will discuss both present results
and future perspectives with the next generation of X-ray telescopes.
