1 Introduction

The Starlink Hierarchical Data System, HDS, allows data files to be constructed with structured and primitive components. They are usually written and read by scientific application programs but it is sometimes useful to create or edit them by hand or to inspect them with no meaning attached to the components.

The HDSTOOLS package contains a number of generally useful tools for this purpose. The tools originated in the Asterix package, which was written at Leicester and Birmingham Universities for analysis of X-Ray data. Asterix is no longer supported so the tools have been extracted to form the HDSTOOLS package, which will be supported by Starlink. HDSTRACE remains the program of choice for displaying the content of HDS objects.

The applications should run as before but the underlying parameter system has been simplified (to the normal Starlink parameter system) and some bugs have been fixed and deficiencies addressed.