The following screenshot displays the library, the library-editor, the QuickREx-View as well as the search-result page for searches in the library. These parts make up the QuickREx-Application.
When you first start the QuickREx Application, it will look like in the screenshot below. The only open view is the QuickREx-View in the lower part of the application-window.
The QuickREx view is used to develop, test and use regular expressions. Details on how the view is used can be found here.
The left hand side in the first screenshot holds the regular expression library in its default state. The regular expression library is used to keep, organize, and search for regular expressions. It is described in detail here. The editor area is used for the regular-expression entry editor which is also described here.