The 35th annual conference on Astronomical Data Analysis Software & Systems 2025 in Görlitz, Germany

ADASS used to hold a regular FITS BoF. Over time, this morphed into a ‘data formats’ BoF. The early days of the FITS BoFs were a Golden Age when most data was written as FITS files that could be read and displayed by programs like SAOImage/DS9 with standardised WCS coordinates. This is reflected in the shiny ADASS Software prizes awarded to SAOImageDS9 and the CFITSIO and WCSLIB libraries. But times move on, and FITS is now an older format competing with a number of new ones, including various different schemas using the flexibility of hierarchical data formats to store data, coordinates and associated metadata with varying degrees of compatibility. Recent data formats BoFs have not reversed the trend and the ship of one format to rule them all may well be over the horizon by now.

This BoF proposal aims to focus discussion on a less ambitious question: have we lost the ability to write general-purpose programs able to get basic information out of most data files of astronomical origin? If so, does this matter? If it matters, can we do something about it? What would it take for a display program to find a data image and its coordinates in both FITS files and a number of different HDF schemas, for example? In effect, can we accept the existence of all the different data formats, but still find common ground in how they might be read?