Track reconstruction in the ATLAS Muon Spectrometer with MOORE 007

MOORE (Muon Object Oriented REconstruction) is a package for track reconstruction in the ATLAS Muon Spectrometer, developed in C++ in the ATHENA framework and according to the standards provided by Object Orientation. This paper describes the MOORE structure and the reconstruction steps, including all the developments that led recently to the use of MOORE in the reconstruction of Data Challenge events, both for physics studies and for a first estimation of its performance as Event Filter, needed for the High Level Trigger Technical Design Report. Efficiency and resolution as a function both of eta and Pt have been estimated with single muons ranging from 3 GeV up to 1TeV. Preliminary results from a first attempt at reconstructing Z->2 muons and H->4 muons are also shown.