  VERITAS, the Very Energetic Radiation Imaging Telescope Array System, is an
array of four 12 m diameter imaging atmospheric Cherenkov telescopes for
gamma-ray astronomy above 100 GeV currently in operation in Arizona. The
VERITAS Collaboration has developed VEGAS, the VERITAS Gamma-ray Analysis
Suite, a data-analysis software package for the processing of single- and
multiple-telescope data produced by the array. The package consists of a core
of six stages as well as visualisation and diagnostic components. It has been
developed in C++ using modern objected-oriented design patterns to be highly
flexible, configurable and extendable. VEGAS utilises CERN's ROOT data-analysis
framework and runs on Linux and Mac OS X systems. The architecture and
structure of the VEGAS package will be described in detail while the data
analysis algorithms are described in additional papers.
