ATLAS Offline Software and its use in Detector Commissioning

Hans von der Schmitt
MPI München

Commissioning of the ATLAS detector at the CERN Large Hadron Collider
(LHC) includes, as partially overlapping phases, subsystem standalone
work, integration of systems into the full detector, cosmics data taking,
and initial running with beams.
The ATLAS offline software, called Athena, is supporting much of this
work.
It is being used offline e.g. for cosmics simulation and analysis, as
well as online for histogramming, event displays and selection in the 
higher trigger levels.
Athena is composed of C++, Python, and some Java parts. The interplay
of the offline, trigger and online frameworks is described.