Stay!

Using Spectacle you can view multiple documents side-by-side, move windows to other displays, or even focus your full attention to a single task.

ShiftIt is an application for OSX that allows you to quickly manipulate window position and size using keyboard shortcuts. It intends to become a full featured window organizer for OSX. It is a complete rewrite of the original ShiftIt by Aravindkumar Rajendiran which is not longer under development.

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.

TaskLayout is a small portable Windows utility which allow saving/restoring of desktop layout (a set of specified apps/windows with corresponding position on screen) in a single click.

Windownaut is versatile window management app that let's you define keyboard shortcuts and active areas on your screen to resize an position the windows on your desktop.

A tiny window management app for the Mac.

MaxSnap is a powerful window manager which lets you:

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.

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.

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.