Alternative Astronomical Software Packages

At a time when the United Nations, in collaboration with Wolfram Research, has selected the Mathematica software package to inform developing countries about available scientific tools, it is important to review other choices of software being used by active scientists around the world. For observational astronomers with large volumes of digital data to be analyzed, the main challenges are data reductions, image handling, model comparisons, interactive fits, data simulations and visualizations, etc. There are several good alternative software packages such as: AIPS, IRAF, MIDAS and IDL The first three packages can be obtained free of charge by contacting the sponsoring institutions. Information can be obtained, via the World Wide Web, from the URLs indicated in the footnotes. IDL is a commercial package that can be used in all kinds of computer platforms and is extensively used in space astronomy (e.g., main language of software reduction packages of missions like IUE, HST, ROSAT, SOHO, etc). All of these packages are able to handle some of the most common commercial and scientific data formats (FITS, CDF and HDF). These software packages provide general tools for image processing and data reduction with emphasis on, but not limited to, astronomical applications. All of these packages have good active customer support strategies, the most useful ones being periodic newsletters, related meetings (e.g., annual meeting on Astronomical Data Analysis Software and Systems), software user groups, bulletin board discussions, FAQs, etc. The purpose of this paper is to present the relative usefulness, available platforms, associated libraries, related resources, of these software packages and the many already existing and potential astronomical applications. This revised version was published online in July 2006 with corrections to the Cover Date.