### 1 Introduction

GAIA is an highly interactive image display tool but with the additional capability of being extendable to integrate other programs and to manipulate and display data-cubes. At present image analysis extensions are provided that cover the astronomically interesting areas of aperture & optimal photometry, automatic source detection, surface photometry, contouring, arbitrary region analysis, celestial coordinate readout, calibration and modification, grid overlays, blink comparison, image defect patching, polarization vector plotting and the ability to connect to resources available in Virtual Observatory catalogues and image archives, as well as the older Skycat formats.

GAIA also features tools for interactively displaying image planes from data-cubes and plotting spectra extracted from the third dimension. It can also display 3D visualisations of data-cubes using iso-surfaces and volume rendering.

Specialised handling of data from the CUPID package provides the visualisation of clumps of emission in 2D and 3D, as ellipses, polygons and boxes.

Interoperability with other SAMP enabled applications is provided so that GAIA can be used as part of a integrated desktop (usually querying the Virtual Observatory).

GAIA is a derivative of the SkyCat1 image display and catalogue browsing tool, developed as part of the VLT2 project at ESO3. Both SkyCat and GAIA are free software under the terms of the GNU copyright.

The 3D facilities in GAIA use the VTK library.

1http://archive.eso.org/skycat/

2http://www.eso.org/vlt/

3http://www.eso.org/