Quicksilver allows you to control your Mac using keystrokes.
Quicksilver makes it easy to quickly find what you need and then take action as you wish. All this is done by simply tapping the keyboard. For example, to locate an application hidden in your file system, activate Quicksilver by pressing a keystroke. Type a few letters of its name, hit Return or Enter, or tab and type to find actions such as Quit or Trash, Email to ..., Login, Move to ..., Get Information, Reveal.
Quicksilver indexes only selected parts of your hard drive and places them in the Catalog. This allows it to quickly locate and display items that match your search. Quicksilver's modular structure allows for interaction with many other applications, such as 1Password, Safari and Microsoft Office.