C4 Menu
From C4 Engine Wiki
The C4 menu can be found in the bottom-left corner of the screen as shown in the screenshot below. Click on the button containing the C4 Engine logo to access the menu. (The bar, or “strip”, at the bottom of the screen is similar to the Windows task bar, and the C4 menu is similar to the Windows start button). The C4 menu provides access to various engine-level utilities as well as commands installed by tool plug-ins.
In the demo, all of the tools that ship with the C4 Engine can be accessed through the C4 menu. The tools run in the engine itself—they are not separate applications.
The window strip containing the C4 menu button appears automatically when the command console is opened, and it is shown when the demo game starts up. It can be removed from an otherwise empty desktop by pressing the Escape key.
Adding commands to the C4 menu
A plug-in module can add a command to the C4 menu by calling the PluginMgr::AddToolMenuItem() function. The MenuItemWidget object passed to this function should have an observer set, and this observer is invoked when the menu item is chosen by the user.

