Every productivity geek's dream, Quicksilver has become one of the essential applications on Mac.
For those of you 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, you don't have to worry about how your folders are arranged. For many, Quicksilver was a godsend in the pre-Spotlight Mac era. Although it's lost some of its importance with the new powerful search and Finder features in Leopard it still remains very much an excellent Mac application.
The search function is very quick and powerful and once you've found what you're looking for you can apply a number of actions like simply launching it, emailing or moving. What's more Quicksilver adapts to the file it's found, so if it's a document you'll get to modify or send it, and if it's an email you'll get to email or copy it. Quicksilver users also like the fact that the application learns from what you search to bring up what you search for or use most.
Quicksilver wouldn't be what it is without its large library of plugins though. This includes everything from dialing a phone number to interacting with iTunes or image and text manipulation. This means you can really customize the application to work according to your needs.
The only downside is the stability issues that Quicksilver seems to have. The application is noted to crash every once in a while.
