Main Window
The application's single top-level window.
Menu Bar
The main window's menu bar, whose nine menus group every Aquila command: File, five study-creation menus, Edit, View and Help.
Toolbar
The button strip beneath the menu bar.
Workspace Status Indicators
Two status lamps at the right-hand end of the toolbar row.
Theme Toggle
A toggle at the top-right corner of the main window that flips the application between the Light and Dark themes.
Studies List
The panel down the left side of the main window, headed "Studies", listing every study in the open workspace with a type icon and the study's name.
Exit Application
Closes Aquila. Closing the main window runs the same shutdown path, which checks for unsaved workspace changes before the application quits.