The Tor browser bundle is a portable package that includes Tor, Vidalia and Torbutton. It also contains a Firefox fork, which can be used together right out of the box. It contains a modified version of Firefox, which aims to address privacy and security issues in the mainline version.
Tor was originally developed, implemented, then deployed by the U.S. as a third-generation onion routing project. Naval Research Laboratory. It was initially designed with the U.S. Navy as a primary purpose to protect government communications. It is used every day by ordinary people, journalists, law-enforcement officers and activists for many purposes.