The FreeGate anti-censorship software was written by the Global Internet Freedom Consortium, and it lets people users to access overseas web sites as fast as they can access local ones --- and it hides who is using the software. So if you live in a country that blocks access to Internet sites such as Twitter and Facebook, you can use the software to get to those sites, and no one will know you're using it. That's how it's being used in Iran.
The software works, in the words of the consortium, "by tapping into an anti-censorship backbone, DynaWeb, DIT's P2P-like proxy network system." In addition, it can be carried on a flash drive, and leaves no trace of itself behind. So you can use it, and no one will be able to find out that you're using it.
Your IP address changes constantly as you use it, so you can't be traced. As for the guts of the system, here's how the Global Internet Freedom Consortium describes it:
DynaWeb is a collection of anti-censorship services provided by Dynamic Internet Technology Inc. (DIT). DynaWeb is a web-based anti-censorship portal. Once users point their web browser at one of the DynaWeb URLs, a web page will be presented similar to the one at us.dongtaiwang.com, with most blocked websites as links. In addition, a user can type in any URL in the box on this page and DynaWeb will fetch the pages for him/her instantly. No software is needed, nor are any settings tweaked on a users computer. But since the Chinese net police watch DynaWebs portal websites closely and block them as soon as they identify them, DynaWeb must indeed be very dynamic. It has hundreds of mirror sites at anytime, and each with a varying IP and DNS domain name, to defeat IP blocking and DNS hijacking. On the backstage, DynaWeb also has mechanisms to proactively monitor the blocking status of each of its mirror sites, and as soon as blocking is detected, it will change the IP and DNS domain name instantly.
You don't need a tool like FreeGate as a way to get around Internet censors. You can also use proxy servers directly, by configuring your browser to connect to proxies. To configure a proxy in Internet Explorer, for example, you select Tools --> Internet Options, click the Connections tab, click LAN settings, check the box next to "Use a proxy server for your LAN," then type in the address of the proxy server. You may also need to change the port number, depending on the proxy server being used. Check out the screenshot below for details.
To help Iranians bypass censors, people all over the world are setting up their own proxy servers. If you want to help, you can set up one yourself --- here are instructions from Austin Heap on how to do it. He also maintains a list of proxy servers that people in Iran can use. In addition, the site proxysetupforiran.blogspot has instructions on how to set up a proxy for Iranian citizens.
A variety of software promises to evade the Internet filters set up by the Iranian government. For example, the Firefox add-in FreeAccess Plus says it can:
Bypass filter of YouTube, del.icio.us, Flickr, technorati.com, friendster.com, flickr.com, livejournal.com, MySpace.com, Hi5.com, and some Persian (farsi) sites in Iran and other countries that blocked these sites.Similarly the Firefox add-in Access Flickr! lets people in Iran get to Flickr, and post and view photos, for example of demonstrations.
The privacy and proxy program Tor has been around for quite some time. It fights against government surveillance of your Internet use, and so Iranians have been flocking to it.
Andrew Lewman, executive director of The Tor Project, told CBS News that "We have seen a doubling of Tor users from IP addresses in Iran over the last few days.
As I've written in another blog post, the U.S. government can help extend democracy in Iran and throughout the world by giving them access to a weapon even more powerful than bullets: information. Congress should sign into law, and Obama should sign the so-called Internet freedom initiative, which would give $50 million for censor-busting technologies like those I detailed in this blog post.