AddIn Manager

Use the Add-In Manager dialog box to load or unload an add-in.
If you close only the visible portions of an add-in (by double-clicking its system menu or by clicking its close button) the form will disappear from the screen, but the add-in is still present in memory.
The add-in object itself will always stay resident in memory until the add-in is disconnected through the Add-In Manager dialog box.