Absorption spectroscopy of gamma-ray burst afterglows: probing the GRB
  line of sight
  GRB absorption spectroscopy opened up a new window in the study of the high
redshift Universe, especially with the launch of the Swift satellite and the
quick and precise localization of the afterglow. Eight-meter class telescopes
can be repointed within a few hours from the GRB, enabling the acquisition of
high signal-to-noise ratio and high resolution afterglow spectra. In this paper
I will give a short review of what we learned through this technique, and I
will present some of the first results obtained with the X-shooter
spectrograph.
