Nima,
Have a look at the LORS package as it is now. You'll see that encompasses three packages:
LORSM (where all the functionality of the application is)
dotlrn-lorms
lorms-portlets
These last two package provide the "hooks" to .LRN. They have a set of service contracts that "link" functionality from your application to .LRN classes/portlets.
I hope that helps,
Ernie