This thesis is a comparative study of two open source astronomical software packages widely used by professional observational astronomers - IRAF by USA's National Optical Astronomy Observatories (NOAO) and MIDAS by the European Southern Observatory (ESO).
We evaluate various aspects of the two software packages - software architecture, application programming environment, graphical user interface, system requirements and installation. A comparative experiment provides an objective evaluation of the two software packages.
We also investigate the current status and future plans for the two software packages, and discuss briefly three of the alternative open source and commercial astronomical software packages available on the market - AIPS, AIPS++ and IDL.
Finally, this thesis makes the claim that IRAF is a feature-packed astronomical software that is difficult to install, and has an unintuitive user interface. In contrast, MIDAS is a professional astronomical software that is simple to install and easy to use. To this end, this thesis recommends MIDAS to prospective users.