Gaia is the ESA cornerstone mission set to revolutionise our understanding of the Milky Way. It is designed to map over one billion stars with three instruments to collect astrometric, photometric and spectroscopic data on stars in the Milky Way and in galaxies belonging to the Local Group, distant galaxies, quasars and solar system objects.
For the ESA Gaia page see http://www.rssd.esa.int/gaia
The IoA has a lead role developing significant elements of the data processing and analysis systems required by Gaia. Specifically the IoA has the lead role in Photometric Analysis System. For details of the DPAC see http://www.rssd.esa.int/gaia/dpac
The IoA is also the lead group developing the Gaia Science Alerts pipeline. The wiki pages for Gaia Science Alerts give more information for the science community - including details of workshops and meetings related to this area.