GUI for .NET refers to ABL applications that have a graphical user interface built with .NET forms and controls. To develop such applications in Progress Developer Studio for OpenEdge, you use the Visual Designer, which provides an accurate visualization of the GUI as you design it and greatly simplifies the coding process by automating much of the code generation. The Visual Designer is integrated with the ABL Editor, giving you easy access to both the graphical design tools and the ABL source code.
GUI for .NET resources in Progress Developer Studio for OpenEdge are:
ABL Form
ABL Dialog
ABL MDI Form
ABL Inherited Control
ABL User Control
These resources are class files that have the same characteristics and requirements as basic classes. When you create a GUI for .NET resource in Progress Developer Studio for OpenEdge, though, it opens in the Visual Designer. By default, when you edit an existing GUI for .NET class, it also opens in the Visual Designer, although you can explicitly choose to open it in the ABL Editor instead.
The Visual Designer subsection of the Progress Developer Studio for OpenEdge online help explains how to use the tools.
ABL Form