Vidalia is a cross-platform graphical controller for the Tor software, built using the Qt framework. Vidalia runs on most platforms supported by Qt 4.3 or later, including Microsoft Windows, Apple OS X, and Linux or other Unix variants using the X11 window system.

Vidalia lets you start and stop Tor, see how much bandwidth you are consuming, see how many circuits you currently have active, see where these circuits are connected on a global map, view messages from Tor about its progress and current state, and let you configure your Tor client, bridge, or relay with a simple interface. Included in Vidalia is an extensive help system which helps you understand all of the options available to you. All of these features are translated into a large number of languages. Vidalia does not work alone, it requires Tor to be useful.