A User Application (or UA), as defined in the ARINC 661 standard, manage Aircraft avionics functions and communicates with a Cockpit Display System.
The UA application module is a wrapper around an ARINC 661 server and client, provided by the J661 project. Go to j661.sourceforge.net for more information.
See also
ARINC661 CDS: A Cockpit Display System (or CDS), as defined in the ARINC 661 standard, is an ARINC 661 graphic Server
Built-in Applications: This article present the built-in Applications distributed with the framework