J4L FO Designer is a visual editor to create XSL-FO files to be used with APEX (version 3, 4 and 5). The benefits of FO Designer are:

• No need to learn XSL-FO.
• Compatible with Apache FOP and Oracle Data REST Services/Apex Listener.
• Easy to use and learn.
• Increased productivity through integrated design and test environment.
• Extended FOP functionality

Possible use cases are

• PDF publishing in several products as Oracle APEX or Apache Cocoon.
• Conversion of XML documents to PDF in integration tools like Oracle BPEL,SAP PI or ESB Mule.
• Generation of PDF files in web applications using AJAX.
• As a generic reporting tool in Java, classes can be converted to XML and to PDF.
• In eBusiness scenarios to collect data from business partners using PDF forms.

A good starting point is the learn by doing tutorial in our User Guide or watching this 5 minutes introduction video.