Quicksilver: Excellent multi-application launcher
Quicksilver is a handy app and folder launcher that has quickly become one of the essential applications on Mac. For those not familiar with Quicksilver, it's an application that lets you reach any program, folder, or file in a few keystrokes. You don't have to go searching through your files or worry about how your folders are arranged. Quicksilver was a godsend in the pre-Spotlight Mac era and remains an excellent Mac application.
The search function in Quicksilver is very quick and powerful, allowing you to find what you're looking for and apply a number of actions like launching, emailing, or moving. The application adapts to the file it finds, allowing you to modify, send, or copy it. Quicksilver also learns from your searches to bring up what you use most.
One of the standout features of Quicksilver is its large library of plugins. These plugins allow you to customize the application to work according to your needs, whether it's dialing a phone number, interacting with iTunes, or manipulating images and text.
The only downside to Quicksilver is its stability issues, as the application is known to crash occasionally. Despite this, Quicksilver remains an incredibly intuitive and powerful multi-application launcher for Mac, recommended for productivity geeks.