On Tuesday I have been presenting on ODTUG Kaleidoskope 2009 in Monterey / California. The presentation was about "PDF Printing with APEX - A cost free alternative". There I have shown and detailed the integration of the open source Java reporting engine "JasperReports" into Oracle Application Express for PDF and RTF printing.
For designing the reports you can easily use the graphical design tool "iReport Designer". It will generate the report definition file for you.
The combination of JasperReports and iReport Designer is a real good alternative to the very expensive reporting solution using the BI-Publisher.
You can download the presentation slides from here.
I will make this integration available for free! Right now I have very many things on my list to do, but I will make it available in the future.
If you are interested in such an integration, please drop me a note at: email@example.com.