Upgrade Oracle APEX in Your Database XE Install
By oracletechnet on Jul 05, 2007
Much welcomed news from the Oracle Application Express (APEX) team: with the release of Oracle APEX 3.0.1, Oracle Database XE users can upgrade version 2.1 integrated with their install. As a result, they now have access to the hundreds of new development features included in versions 2.2 and 3.0, making XE even more of a database app development powerhouse than before.
Do note if upgrading that you will lose your ability to use the Oracle APEX interface to perform some database management functions. You'll have to use SQL*Plus or SQL Developer instead.
See this document for a full explanation of this release's impact on XE.