Abstract:The IMS Learning Design specification aims at capturing the complete learning flow of courses, without being restricted to a particular pedagogical model. Such flow description for a course, called a Unit of Learning, must be able to be reproduced in different systems using a so called run-time environment. In the last few years there has been several tools implementing such functionality, but most of them are standalone and do not benefit from the integration with a Learning Management System. This paper describes GRAIL, an IMS Learning Design run-time environment supporting all three levels of the specification and fully integrated with the .LRN Learning Management System. The paper describes its functionality, explains how each level is implemented, shows the differences with other CopperCore based environments, and analyzes its integration with the rest of .LRN services and other specifications such as QTI and SCORM.