Tor enables its users to surf the Internet, chat and send instant messages anonymously, and is used by a wide variety of people for both licit and illicit purposes. Bureau of Democracy, Human Rights, and Labor and International Broadcasting Bureau, Internews, Human Rights Watch, the University of Cambridge, Google, and Netherlands-based Stichting NLnet.

The EFF acted as The Tor Project's fiscal sponsor in its early years, and early financial supporters included the U.S. In 2006, Dingledine, Mathewson, and five others founded The Tor Project, a Massachusetts-based 501(c)(3) research-education nonprofit organization responsible for maintaining Tor. In 2004, the Naval Research Laboratory released the code for Tor under a free license, and the Electronic Frontier Foundation (EFF) began funding Dingledine and Mathewson to continue its development. The first public release occurred a year later. The alpha version of Tor, developed by Syverson and computer scientists Roger Dingledine and Nick Mathewson and then called The Onion Routing project (which was later given the acronym 'Tor'), was launched on 20 September 2002. Onion routing is implemented by means of encryption in the application layer of the communication protocol stack, nested like the layers of an onion. Reed and David Goldschlag, to protect American intelligence communications online. The core principle of Tor, onion routing, was developed in the mid-1990s by United States Naval Research Laboratory employees, mathematician Paul Syverson, and computer scientists Michael G.

4.9 Relay early traffic confirmation attack.

4.6 Some protocols exposing IP addresses.

4.2.1 Autonomous system (AS) eavesdropping.

Comparison of Internet Relay Chat clients.

Overlay network, mix network, onion router, Anonymity application

Unix-like, ( Android, Linux, BSD, macOS), Microsoft Windows, iOS

Tor dark web and wan