The ATLAS Open Data project has for many years successfully delivered open-access data, simulations, documentation and related resources for education and outreach use in High Energy Physics and related computer sciences based on data collected in proton-proton collisions at 8 TeV and 13 TeV at the LHC at CERN. These resources have found substantial application worldwide in universities, in schools, and in other public settings. Building on this success and in support of CERN's Open Data Policy the ATLAS experiment plans to continue to release 13 TeV data for educational purposes and -for the first time -also for research purposes. This contribution summarises the landscape of the existing ATLAS Open Data project: what resources are available and how have they been used, and what is planned for the future.