Many modern USB mice are fitted with a scroll wheel. The WimpScroll module offers low-level support for such mouse wheels. It receives information from the USBHID module, which will be converted into a approprate action.

WimpScroll tries to identify the window currently under the mouse pointer and will send appropriate scroll requests to that window. As some applications don't behave as expected, a number of different scroll methods have been implemented in the module.

Please note that some keyboards have a scroll wheel present as well. Such a wheel will behave in the same way as a mouse wheel, i.e. it will scroll the window currently under the mouse pointer. The window is not required to have the input focus.