Oracle APEX Listener‘s primary function is to serve as a Java friendly alternative to mod_plsql. The most well known application that uses mod_plsql being APEX. However the Listener is not restricted to providing HTTP access to APEX, it can provide HTTP access to any PL/SQL procedure that mod_plsql can.
Similarly the Resource Templates functionality we have introduced in the latest APEX Listener Early Access Release is not dependent on APEX. Resource Templates can be used to expose any data stored in the database via HTTP, regardless of whether that data is managed by an APEX application or not. To be clear you don’t need to use APEX to be able to use Resource Templates.
P.S. If you’re using the new Resource Templates functionality, I’d love to hear about it, let me know the good or bad here or in the forum, thanks!