FillX
Realtime intelligent window resizing for the X Window System
Usage
Using your system's keyboard settings to set up a hotkey to launch FillX is recommended. Once it's running, click on a window, then move your mouse to where you want the window to go. Pressing Alt will change whether the script maximizes height or width. Click again to finalize.
Installation
FillX requires Python 2.7 and Python-Xlib. If xwininfo is installed, FillX will use that for window selection; otherwise, the active window will be used.
"FillX" is a play on the phrase "fill in," the opposite of "in" being "ex," and the name of the Linux window system, X.
Just not a very clever one.