LHC Computing – the First 3 Decades

Computing for the Large Hadron Collider (LHC) at CERN arguably started shortly after the commencement of data taking at the previous machine – LEP – some would argue it was even before. Without specifying an exact date, it was certainly prior to when today’s large(st) collaborations, namely ATLAS and CMS, had formed and been approved and before the LHC itself was given the official go-ahead at the 100th meeting of the CERN Council in 1995. Approximately the first decade was spent doing research and development; the second – from the beginning of the new millennium – on grid exploration and hardening; and the third providing support to LHC data taking, production, analysis and most importantly obtaining results.