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.
ShiftIt installs itself in the menu bar (optionally it can be completely hidden). It provides a set of actions that manipulates windows positions and sizes. Following is an example of list of actions available: