User scripts can use this object to access "custom" properties--variable and functions defined in the page--set by the web page. This is done by bypassing Greasemonkey's XPCNativeWrapper-based security model. unsafeWindow is shorthand for window.wrappedJSObject; it is the raw window object inside the XPCNativeWrapper provided by the Greasemonkey sandbox.
unsafeWindow is insecure, and should be avoided when possible. User scripts absolutely should not use unsafeWindow if they are executed for arbitrary web pages, such as those with