Many thanks go to Allan Brighton, Thomas Herlin, Miguel Albrecht, Daniel Durand and Peter Biereichel, who are responsible for the SkyCat developments at ESO, in particular for making their software free for general use. GAIA and SkyCat are both based on the scripting language Tcl/Tk16 developed by John Ousterhout and the [incr Tcl]17 object oriented extensions developed by Michael McLennan. They also make use of many other extensions and scripts developed by the Tcl community. Thanks are also due to the many people who helped test out GAIA and iron out minor and major problems (in particular Tim Jenness, Tim Gledhill and Nigel Metcalfe) and all the users who have reported bugs and sent support since the early releases and continue to do so.
The 3D facilities of GAIA make extensive use of the VTK library. Also a free library.
GAIA was created by the now closed Starlink UK project, funded by the Particle Physics and Astronomy Research Council (PPARC) and has been more recently supported by the Joint Astronomy Centre Hawaii funded again by PPARC and more recently by its successor organisation the Science and Technology Facilities Council (STFC).