Abstract: The Avionics Program Expert (APEX) is an automatic code generation tool for the Ada programming language (MIL-STD 1815A). It provides the programmer using APEX with the ability to quickly create a graphical representation of his initial program design. The graphical representation used by APEX is akin to a flowchart, but the interactive capabilities of the tool make design creation much faster and more efficient. Once the programmer has created his complete (or even partial) representation of a program, Ada code can then be generated with (from) APEX. The APEX program representation provides the user with three different, yet consistent, views of his program. The first view allows the programmer to lay out his initial Ada package specifications; this view is called the APEX view. A second view allows the programmer to create and manipulate complex data structures and define local variables; this view is the Data Structure view.