Hi Elena,
I have both first hand experience in developing for .lrn and moodle. Below is not everything but should give you some preliminary comparison:
* custom features and functionality
- .lrn is better than moodle since .lrn is built on a web framework (openacs). OpenACS has a more mature API for developing web apps.
* out of the box
- moodle has better out of the box functionality, it may depend on what you need. But in general moodle has a lot of functionality for the edu sector needs
- moodle is also easier to install
* scalability
- .lrn will scale better than moodle. .lrn software stack is built to scale (aolserver, postgres/oracle, unix) The number of users using a .lrn install shows this. However moodle can scale also, I am currently working for a company that is hosting 35k moodle users.
* integration
- moodle has more out of the box integration tools. I believe due to more number of moodle install it was integrated with more external systems. moodle has more authentication and enrolment plugins.
Hope this helps.
