Up to now, to create an application over an eXo portal such as DMS, WCM, CS and KS, we need to modify files into the "portal.war". This has many painful consequences, such as:
It is quite hard to manage from the support point of view since we never know if or how the customer changed his eXo product.
It is hard to be able to package several eXo products (WCM, CS...) as we need to merge everything manually which is quite error prone.
Finally, at the very beginning, eXo was developed to be able to support several portal instances (which also means several portal containers) but with the time several bad practices made it impossible. So it was important to review the whole code base in order to help/enforce all the GateIn developers to follow the "good practices".