The US has long played a leading role in software and computing R&D across its focus areas of core software, event I/O and distributed computing. Given the compute-limited physics of ATLAS, a particular focus has been leveraging as broad an array of computing resources as possible, including supercomputers, DOE Leadership Class Facilities (the largest supercomputers), and commercial clouds as well as the grid.
In 2018, preparing for the tremendous growth in computing requirements that the HL-LHC will bring for ATLAS, US ATLAS created an R&D activity specifically focused on HL-LHC computing R&D, with the following activity areas.