Tor is a software project that helps you defend against traffic analysis, a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security. Tor protects you by bouncing your communications around a distributed network of relays run by volunteers all around the world: it prevents somebody watching your Internet connection from learning what sites you visit, and it prevents the sites you visit from learning your physical location. Tor works with many of your existing applications, including web browsers, instant messaging clients, remote login, and other applications based on the TCP protocol. Hundreds of thousands of people around the world use Tor for a wide variety of reasons: journalists and bloggers, human rights workers, law enforcement officers, soldiers, corporations, citizens of repressive regimes, and just ordinary citizens.
Privoxy is a web proxy program, frequently used in combination with Tor and Squid. It has filtering capabilities for protecting privacy, modifying web page data, managing cookies, controlling access, and selectively removing content such as ads, banners and pop-ups. It can be customized and has application for both stand-alone systems and multi-user networks. The program is based on the Internet Junkbuster and is released under the GNU General Public License. It runs on Linux, Windows, Mac OS X, OS/2, AmigaOS, BeOS, and most flavors of Unix. Almost any web browser should be able to use it. Privoxy combined with Tor is also used around the world to bypass Internet censorship. (wikipedia)
OperaTor is software bundle containing portable Opera browser with integrated Tor and Privoxy. There is not need to install it. You can carry it to any place in your USB. Use it to bypass any censorship which stops you from using Internet e.g. you can bypass the Internet restrictions in your school, office, net cafe’, etc.
OperaTor does not leave any data on your computer. Your computer will be in the same condition which was before using OperaTor. No cookies will be installed and no registry chage will be done because of use of OperaTor.
There is just one problem that it is not speedy. In my testing, the maximum download speed of a webpage was at 25 KBs. This is very slow. One more fact is, it can not be used to download torrents by HTML/JAVA based applications. It will reveal your IP contrary to UltraVPN which hides you.