Reddit today announced that it is open-sourcing almost all the code that powers its site and community. Ars Technica interviewed reddit co-founder Steve Huffman on why one of the web's most popular social news sites would hand over the technological keys to its success.

As one of the first social news sites to appear in 2005, reddit now sports over 4.5 million monthly unique visitors who generate 120 million pageviews a month. The site experienced its largest growth spurt—a whopping 1,033 percent—in December 2007 with just over 4.1 million unique visitors, and 23 percent of reddit's users have registered just this year after the company introduced its user-generated category area, called reddits.

With all this impressive growth in the past year, my first question for Huffman was: "why?" Many could argue that open-sourcing the back end of a site that's on a roll like reddit's would be grounds for getting someone committed. But Huffman isn't worried. Reddit "offers an alternative to mainstream media," according to its co-founder, and they aren't worried about competitors trumping them with their own technological bread and butter. If the competition was going to pounce, "they would've replaced reddit by now."

Most of reddit's formula for success is already public. The site offers a comparatively minimal, text-centric UI for voting on stories, leaving comments, and browsing reddits. Clearly, the user-generated nature of reddits and their ability to be public, restricted to select users, or completely private was a major traffic boost for the site, and open sourcing almost all of its code is a move to bring in even more traffic.

Surprisingly, reddit is powered by a team of just five members, including Huffman. The decision to open source was also fueled by the potential for building the site based on community ideas and code. "We have a huge community of programmers on reddit who are constantly telling me how to do my job," Huffman explained. "Now we have a chance to see if they can walk the walk and actually help us out." Reddit fully plans to accept new features programmed for the site from the community, though it doesn't quite have a solid process in place for incorporating user-contributed code just yet.

Another major contributing factor in reddit's decision is the company's commitment to both the community and transparency. A major criticism of social news sites, especially digg, is that they are either easily gamed, rigged by a secret society of editors and "news mafia," or both. By making all of its code available—including the front page's algorithm—reddit won't have to worry about those accusations anymore.

"Our value is more in the loyalty of our community than it is in our technology," Huffman said. The majority of reddit is built from open-source technologies anyway. "It seems only fair that we release the code of reddit" back to the community. "I know I have learned an incredible amount in the last three years working on reddit," Huffman continued. "I hope others might find value in it."

Not all of reddit's code will be released, however. Huffman told me that while about 95 percent of reddit's code base is getting released at code.reddit.com under the CPAL license (the same one Facebook used to open source its own platform), including the rating algorithm that chooses which stories float to the front page, the company will keep specific portions of code under wraps. For obvious reasons, these code portions that will remain locked away are related to preventing cheating, gaming the system, and fighting spam.

Disclosure: Reddit is owned by Condé Nast, Ars Technica's new parent company.