Let's start with the classic simple program: Hello World.

Create a new program.

Next, select Rich Client for the Task type. This is what makes the program run as a Rich Client program.

Create at least one variable.

Because this is a Rich Client task, the Main Form will default to Rich Client Display. This is the form type that will be used for Rich Client programs, rather than the GUI Display type used for Online programs.

Now create your form, as you usually would, adding text and fields from the Toolbox and Variables pane.

Now run your program as usual, using F7.