From Wikipedia:
Automator is an application developed by Apple for Mac OS X that implements point-and-click (or drag-and-drop) creation of workflows for automating repetitive tasks. Automator enables the repetition of tasks across a wide variety of programs, including the Finder, the Safari web browser, iCal, Address Book and others. It can also work with third-party applications such as Microsoft Office or Adobe Photoshop. Automator was first released with Mac OS X Tiger (10.4).
http://en.wikipedia.org/wiki/Automator_(software)