.LRN is a vertical application which combines a variety of standard OpenACS application packages with a replacement for the standard subsite package named "dotlrn".

The dotlrn package imposes a fixed structure on the website that serves as our e-learning platform framework.

The dotlrn functionality includes:

• A web-based administration interface for the creation of terms, departments, subjects, and classes. This hierarchy is fixed when the datamodel is created but the installation files are relatively easy customize.

• The dotlrn applet service contract is defined in the dotlrn package. The appropriate applets are called automatically when a class or community is created. The result is that new classes and communities are instantiated with a pre-defined set of applications and their associated portlets, and with a pre-defined portal page structure. These are all configurable by package parameters.

• When new classes and communities are instantiated, a membership group is automatically created, along with relational segments which define Professors, administrators, students, etc. These relational segments are hard-wired but, again, fairly easy to customize by those willing to hack code.

• At the global level, sitewide-groups are defined for professors, students etc. There are no permission semantics associated with these groups. While this confuses newcomers to .LRN at times, it makes sense: a member might be a professor of the university, but at the same time a mere student in a particular class. Likewise, graduate students at a university often work as teaching assistants in particular classes.