Windows only: Free, open-source application KDE Window-Sizer resizes and moves windows when you click anywhere inside the window while holding the Alt key. To move a window, then, hold Alt and left-click and drag anywhere in the window to move it—this behavior mimics the move behavior available in the KDE Linux desktop environment. Likewise, to resize a window from anywhere, just hold Alt and then right-click and drag anywhere in the window. Additionally, the application will snap any window to the edge of your monitor by Alt-right-clicking or Alt-resizing the window, which really helps maximize screen real estate. It may sound confusing at first, but give it a try and you’ll quickly appreciate the new functionality,

Is it April Fools Day and no one told me?

Why does the group that makes a very popular linux desktop put out Windows-only software?

The secret is in the link.