D. Wicke (Fermilab)
Abstract: The D0 experiment faces many challenges enabling access to large datasets for physicists on 4 continents. The strategy of solving these problems on worlwide distributed computing clusters is followed. Already since the begin of TEvatron RunII (March 2001) all Monte-Carlo simulations are produced outside of Fermilab at remote systems. For analyses as system of regional analysis centers (RACs) was established which supply the associated institutes with the data. This structure which is similar the the Tier structure foreseen for LHC was used in autumn 2003 to rereprocess all D0-data with the uptodate and much improved recontruction software. As the first running experiment D0 has implemented and operated all important computing dask of a high energy physics experiment on worldwide distributed systems. The experiences gained in D0 can be applied to judge the LHC computing model.