As of June 28, 2010 the Oracle APEX listener is available for download on the Oracle Technology Network (OTN) here. The APEX listener in combination with a J2EE Web Server is a drop in replacement for Apache / ModPLSQL. Since Oracle Application Express (APEX) is deployed within an Oracle database you need some thin mid tier to facilitate the communications between the browser and the database. The Oracle APEX listener does this, it takes URL gets and posts and maps them to database calls; then returns the generated HTML to the browser. The Oracle APEX listener not only services all versions of Oracle APEX it can also service any PL/SQL Web tool kit application.
For those who follow this technology closely you will note this is the third way to expose Oracle APEX (and Oracle web toolkit) applications on the web. The Oracle HTTP Sever (OHS) is distributed with the Oracle database as well as our middleware. The Oracle HTTP Server bundles Apache 2 with the PL/SQL module (mod_plsql). This is good for customers / developers who want to run Apache. A second alternative is to use the Embedded PL/SQL Gateway (EPG), which is can be enabled by running database scripts and runs out of the database using XDB. This is good for less demanding workloads that want the simplicity of no mid tier. Ideal for a notebook. So this brings us to the new APEX listener which is the third way of integrating Oracle APEX. The Oracle APEX listener can run with Oracle Web Logic Server (WLS) or Glassfish, or most any Java web server. This configuration is ideal for customers / developers who use a Java stack, use Oracle Fusion Middleware (FMW) or like the simplicity of deploying in a Java Web Server.
From my perspective the Oracle APEX listener is the way to go for most, in that it does not lock you into any specific version of Apache (you can of course front end the APEX listener with Apache), and it offloads the web serving from the database when using EPG. So the APEX listener addresses major concerns of our customers (1) no Apache version lockin, (2) synergy with the Java stack (3) external to the Oracle database.
To learn more about how to install, use, and manage the Oracle APEX listener you can visit our OTN page. If you have support for the Oracle database you can call Oracle support. If you want to discuss the APEX listener in our OTN forums you can do so here.