The reason why Oracle is the leading the market for too long a time when it comes to the enterprise software is that they are flexible and adaptable and have got mettle to learn from their not-so-successful products.
Oracle Internet Application Server (iAS) is not something which is talked about highly the middleware circles. Understandbly, that's not an official line from Oracle, but iAS lacks in stability, reliability and performance and it's OC4J is also of low quality compared to Oracle standards.
Oracle learns, and learns fast. They have now turbo-charged and terrorism-proof their middleware offerings in this regard by acquiring BEA, and by presenting Oracle WebLogic Server, an industry proven, time beaten Application Server plus much more. It replaces OC4J and though primarily it targets the JAVA, it also protects the legacy investments in Oracle Forms and Reports.
With Sun in Oracle's temple, JAVA will surely be the blue-eyed daughter and WebLogic Server proves that. With Oracle Weblogic Server, Oracle Coherence, and JRockit, Oracle Weblogic Server is one of the most important pillar in Oracle Fusion Middleware.
DBAs must learn architecture, installation, deployment, configuration, and maintenance of Oracle WebLogic Suite 11g.