(The Onion Router) The largest implementation of onion routing, which is a method for transmitting data anonymously over the Internet. Run by volunteers, there are approximately a thousand Tor proxy servers on the Internet that provide the routing paths. Tor can be used by any TCP application that supports a SOCKS proxy server. In addition, there are Firefox bundles that include Tor and a modified Firefox application. For more information, visit www.torproject.org. See onion routing.