The Crow Designer is a visual editor for building graphical user interfaces. Interfaces are saved in files of the GuiXml format and may be involved in applications by means of the GuiLoader library. During editing, the following instruments are available to a user: a palette of GUI controls, an object tree, an editor canvas, and a hierarchical property explorer. The property explorer allows you to work with nested objects and arrays as well as with several selected objects simultaneously. The designer uses widgets of the GTK+ library as a GUI control kit.