Realtime intelligent window resizing. Tiling++
To begin FillX, hold down the Windows key and middle-click on a window. While holding down the middle mouse button, move your mouse to the desired window location. The window will expand to the borders of neighboring windows. Press and release the Windows key to toggle between maximizing the horizontal and vertical window dimensions.
FillX is a standalone AutoHotkey script, and will run wherever AutoHotkey 1.1+ is installed. To make it portable, rename the AutoHotkey executable to FillX.exe and place it in the same directory (e.g. a thumb drive) as the script. Running the executable will launch the script even if AutoHotkey is not installed.