Tor is a tool used for anonymising web browsing and communications through encryption and proxy servers. Tor’s plugin,Torbutton for Firefox is well known and has provided and easy way to securely enable or disable the browser’s use of Tor browsing to prevent IP address leakage, cookie leakage, and general privacy attacks and provide the user with online anonymity when required.
Well plans are now afoot to drop the plugin and create a standalone fork of the Firefox browser to allow secure Tor browsing from within a separate Tor browser.
In March 2011 The Tor Project was awarded the Free Software Foundation’s 2010 Award for Projects of Social Benefit on the following grounds: “Using free software, Tor has enabled roughly 36 million people around the world to experience freedom of access and expression on the Internet while keeping them in control of their privacy and anonymity.
You can read more about the decision plans to take Tor towards a separate browser over on the Tor blog.