The DoD's [Department of Defense's] Advanced Distributed Learning (ADL) Initiative is designing a framework of commercial standards, technical specifications, and business rules to enable plug and play interoperability of learning technologies. The Total Learning Architecture (TLA) framework will allow education and training products to interoperate with each other, with existing learning support systems, and with other DoD systems. The purpose of this report is to guide Command decisions toward a shared vision and end-state that benefits every warfighter individually and the entire DoD holistically. It describes and summarizes the research performed by the ADL Initiative in 2019 within the TLA research portfolio. It includes four appendices that detail the TLA's latest functional requirements, recommended draft standards, an initial architecture that conforms to the DoD Architectural Framework (DoDAF), and a Software System Design Document built around the 2019 TLA Reference Implementation. The target audience includes senior DoD leaders, educational institutions, and program managers of DoD training systems.