Pregap4 provides interfaces to define the batch of data files to be processed, which modules are to applied to them; to configure the modules, and to start the processing. It also provides mechanisms for adding and removing modules, but this facility will be used far less often than the others.
Pregap4 supports two styles of windowing. The default method is a compact mode, with the alternative being "separate" mode - similar to gap4 and spin.
![[picture]](pregap4_separate.unix.gif)
This is the "separate" window style. Here the main window is always visible, with commands in the main window bringing up new windows. In the picture above the configure window can be seen on top of the main window.
The second style is "compact" mode.
![[picture]](pregap4_compact.unix.gif)
In the compact picture above the most common top level windows are "pages" in a tabbed notebook. The benefit is greatly reduced screen space and quicker controls, but the text output window is no longer permanently visible. The Window Style can be changed using the options menu (see section Window Styles).