CMS Software Architecture Software framework, services and persistency in high level trigger, reconstruction and analysis

A framework is in place where physics software modules can be incorporated. It covers a range of applications from high level trigger to offline analysis. It provides persistency along the lines recommended by RD45. Basic computing services are accesses via LHC++ libraries. Now it is in use in Test-Beams and high level trigger studies. This note describes the architecture of CMS software with emphasis on the mechanisms put in place to satisfy the requirements identified in the Computing Technical Proposal. Particular attention is paid to the problem of persistency.