FITS image display and simple analysis
Spydr (pronounced like spider) basically is an FITS image viewer. It can work as a stand-alone application but is best integrated in a Yorick-based data-analysis work-flow (Yorick is an interpreted language specialized in numerical computations and scientific graphics). It includes tools to zoom, produce cuts, histograms, Gaussian/Moffat fits, PSF fits (inc. FWHM and Strehl). Can work on single images, sequences of images or data cubes.