Windawesome!

AltDrag allows you to move and resize windows much easier. When you have it running you can simply hold down the Alt key and then use your mouse to drag any window, and it doesn't matter where in the window you click. This is especially useful in netbooks, with respect to the small screen and touchpad. It simply allows you to do more with less mouse movements.

HyperDock adds Windows 7 like features and more to Mac OS X.

WindowGrid is a modern window management program that allows the user to quickly and easily layout their windows on a dynamic grid.WindowGrid gives functionality to the normally useless right mouse button when moving a window. Doing this will enable the grid snap mode.

MaxSnap is a powerful window manager which lets you:

SizeUp allows you to quickly position a window to fill exactly half the screen (splitscreen), a quarter of the screen (quadrant), full screen, or centered via the menu bar or configurable system-wide shortcuts (hotkeys). Similar to "tiled windows" functionality available on other operating systems.

xmonad is a dynamically tiling X11 window manager that is written and configured in Haskell. In a normal WM, you spend half your time aligning and searching for windows. xmonad makes work easier, by automating this.

KDE Mover-Sizer is a lightweight program enabling KDE-style alt-click moving and resizing for Windows XP, 7, 2000, 2003, Windows Server, and Vista.

bspwm - A tiling window manager based on binary space partitioning

Easy Move+Resize is based on behavior found in many X11/Linux window managers, adding easy modifier key + mouse drag move and resize to OS X.

Mosaico is a tiling window manager for Windows. It saves the position of the windows on your desktop so that you can restore them later. It also tiles them so that they fill the whole screen surface and you get more information at once.

Taekwindow is a simple, lightweight and free Windows program that allows you to move and resize windows by dragging them with the Alt key, similar to many X11 window managers.