The OpenEdge Visual Designer, available as an Progress Developer Studio for OpenEdge plug-in, is the WYSIWYG designer tool for building GUI for .NET applications. While visually designing a form, an ABL class file is generated for the form. The Visual Designer keeps track of all .NET assemblies and resources that you use in a project.

Within a GUI for .NET application, you can plan a gradual migration by converting some of your main windows to .NET forms and leaving the rest of the UI as ABL windows. This is possible because you can display ABL windows alongside .NET forms. OpenEdge allows parenting of forms to windows and windows to forms using the OpenEdge PARENT attribute on the window handle.