An aeronautical software application development workbench handling the production of a graphical human-machine interface on one or more display equipment systems comprises computer means processing software tools for creating, simulating or integrating graphical functions or “widgets” and logic functions for modifying the content of the graphical functions according to incoming events on the display equipment system or systems, said widgets being described in a file called “Definition File”. The workbench includes a single graphical editor for designing the user application, the technical characteristic of which is to produce a structured language which describes each widget contained in the definition file and which associates consumed variables called “input plugs” with the modifiable attributes of said widget and produced variables called “output plugs” with the notifications of the events produced by said widget.