Gamma-ray busrts as probes of high redshift galaxies and their environments

The launch of the Swift mission has revolutionised the study
of the Gamma-Ray Bursts, enabling the optical follow-up of the early afterglow.
Thanks to the fast broadcast of the GRB coordinates
and to the rapid response mode systems built up in 8-meter class
telescopes, these afterglows have be observed from hours down to a few
minutes after the GRB explosion. The high signal-to noise achievable
allows us to acquire medium-to-high resolution spectra, which carry a lot of
information both on the GRB environment and the Inter-Stellar Medium
of high redshift galaxies. I will give a short review of what we have
learned through the medium-to-high resolution spectroscopy of GRB afterglows,
mainly with UVES and X-shooter at the VLT.