A new and exciting piece of functionality that comes with the new versions of OracleAS Portal (starting with 10g – 10.1.4) is the Content Management Event Framework (CMEF).
CMEF enables you to extend OracleAS Portal’s content management functionality by adding programmatic hooks to certain pre-defined portal events. The framework publishes these events to an Oracle database queue. This allows third party programs to subscribe to these events and to use the APIs to extend your portal. In this way, you can use page and item related events within a portal to trigger actions within one or more external applications.
The CMEF can be programmed using the OracleAS Portal PL/SQL API’s.
Some information provided in Oracle documentation