Description from the author:
"The Panel Display System provides a simple yet powerful method by which an application developer can create an interactive user interface without requiring OS/2 Presentation Manager (PM).
The method by which information is presented by the application to the end user and information from the end user is returned to the application is via a construct known as a 'PANEL'.
A panel is defined by the developer and displayed by the application thru calls to the REXX application programming interface (API), herein referred to as the REXX Panel Display API or rxPD, or thru calls to an optional high level language interface.
As the end user interacts with a displayed panel, the PD system takes care of most keystrokes and combinations of keystrokes, known as chords, without the application having to interpret these keystrokes.
The application can, however, be written to handle any keystroke that might require special handling other than the PDS default for that key or chord."