Many IAEA Member States are actively engaged in activities related to Accelerator Driven Systems (ADS), with some planning the construction of new ADS facilities. A key requirement for these systems is the use of Low Enriched Uranium (LEU) rather than High Enriched Uranium (HEU) fuel for their subcritical assemblies, in line with non-proliferation objectives. This new IAEA publication presents the outcomes of a Coordinated Research Project on LEU-based ADS systems. It features both experimental and analytical work, offering insights into system design, operational analysis, and potential applications. The report is a valuable resource for those involved in LEU ADS project planning, research programme development, and the analysis of facility operations and experiments. Whether initiating a new ADS project or refining an existing one, this publication provides practical guidance and technical depth to support project development.