Using the IMD LD specification, the professor is able to indicate the moment (which could be based on conditions) in which a role is going to do an activity and which materials and services are going to be used. Integrating IMD LD into .LRN, the professor is able to use all the services provided by .LRN, such as forums for asynchronous interaction, chat as synchronous interaction, assessments to evaluate the e-learning process (students and contents), the evaluation package (grade book) to support a a variety of learning and support activities, etc. And all of this is done in a centralized way, from an IMS LD editor.

The main idea is to load an IMS LD document (which is an XML document) and play it. To play an IMS LD document is nothing more than to peform the activities prescribed in the document with its related enviroment which defines the learning objects and services, and this is when the interaction with the .LRN services begin. The imsld package is able to detect and indicate what .LRN service is the most indicated one to perform a given IMS LD service. The activities will follow the sequence prescribed in the IMS LD document, each member of the course will perform a specific set of activities according to the member's role inside the course. The professor is able to decide the different roles that the course supports, and which role can do what at any given time during the course life, and following the defined sequence.

With the imsld package, the professor is able to let the learner choose betwen the activities, make the learner follow a specific sequence or use a combinaiton of both sequenced and learner's choice activities. And that's not all, the professor is also able to define the sequence of the learning activities using conditions and properties that change according to the learner behavior during the course (as defined at the the level B of the Learning Design Specification). Moreover .LRN can take advantage from the power notification system in order to send messages and set new activities based on events (as defined at the level C of the Learning Design Specification)

The imsld package provides an IMS LD editor, an IMS LD player, an IMS LD viewer and an IMS LD importer/exporter. Each one of these is described later on this document.