Atwood, who left Stack Exchange — the company that manages Stack Overflow and a number of other similar sites — about a year ago, launched his new venture on Tuesday with a blog post in which he lamented the fact that commenting and user forums have not changed much in the past decade. The vast majority of these platforms, he says, still fail to capture real conversation and are too difficult or expensive to implement.

Figuring out who to trust is the holy grail

The Stack Overflow founder says his new platform, which is known as Discourse, differs from other commenting systems in a number of ways — including the fact that it is fully open source. Atwood used the blog-publishing platform WordPress as a model (see disclosure below), and says the company will rely on selling hosting, support and other services for revenue.

Discourse has raised funding from a group of venture backers including Greylock and SV Angel, although Atwood wouldn’t say how much (another hosted commenting solution, Livefyre, also just closed a round of financing).

In addition to some other innovations, such as links that automatically expand within a comment (in the same way Twitter’s “expanded tweets” do), Atwood says he is trying to build a reputation system that will grant users new abilities based on the level of trust the platform has in them. Although he doesn’t provide a lot of detail, in a comment on a Hacker News discussion thread he suggests that it will be based on behavior such as flagging abusive posts.

Measuring trust and rewarding good behavior is something online communities have been trying to do for years, with mixed success. Some believe that sites like Slashdot — which has a moderation platform that awards “karma points” for certain behavior and appoints moderators automatically — have a good solution to the usual problems of trolling and flame wars, while others argue that these systems are almost always fatally flawed. Metafilter (which charges users $5 to become members) has many fans, but it is also a relatively small community. Branch is another attempt to reinvent user forums and discussion as invitation-only hosted conversations.

Trust takes effort, not just algorithms

Atwood says he wants to use a badge system for rewards (something Huffington Post also uses), but Gawker founder Nick Denton said in an interview last year that a similar reward system his sites used was a “terrible mistake,” because it was easily gamed and encouraged the wrong kinds of behavior. Denton has since completely revamped Gawker’s commenting system in an attempt to make reader comments the centerpiece, as well as a potential business model.

As my colleague Jeff Roberts noted in a recent post, the Huffington Post has also launched what it hopes will be a new feature called Conversations, which allows popular comments to become full-fledged blog posts of their own. The Verge — a tech blog run by Vox Media — is doing something similar with its site, in order to try and encourage more discussion and community. But both take a lot of manual effort.

Veteran blogger Anil Dash pointed out in an insightful post in 2011 that one of the only ways to maintain and encourage a healthy conversation — regardless of what platform you use — is to be involved in those discussions yourself as much as possible (a point Bora Zivkovic of Scientific American also made recently). Unfortunately for publishers looking for a quick or inexpensive fix, that kind of engagement is almost impossible to automate.

Disclosure: Automattic, the maker of WordPress.com, is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.

Post and thumbnail images courtesy of Shutterstock / Sam72 and Yan Arief Purwanto

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The New York-based startup said late last night it has raised a Series B funding round from new investors Index Ventures and Spark Capital along with original investor Union Square Ventures. The new capital follows a $6 million first round in May last year from investors Ron Conway, Chris Dixon, Caterina Fake, Naval Ravikant, Nirav Tolia, Joshua Schachter, Micah Siegel, and Bob Pasker.

Along with the new money, the company has also changed its name to Stack Exchange Inc., which was previously the name of its network of sub-sites covering more than 40 different areas including things like English, photography and cooking. The original name came from the programming term, which was where the company began its focus: as a destination for coders. But now, the company is clearly signaling that its future is much broader than programming and that its model can work for many more areas.

The newly renamed Stack Exchange has surged because of its very ordered way of answering questions. It works by focusing on specific verticals and building up experts within those areas who can answer incoming queries. The result is an impressive answer rate of more than 80 percent overall, and in some vertical subject areas, well over 90 percent. That has translated into a lot of users. Last month, the site hit 19 million users to crack Quantcast’s list of top 300 sites.

CEO and founder Joel Spolsky didn’t exactly say what the new money will be used for, joking instead that the company is now planning on buying more t-shirts, snacks and a ping-pong table. But it’s a good bet the company will be growing its team as it adds more vertical sites to Stack Exchange, which is approving a new site a week. Stack Overflow was profitable last year before it launched Stack Exchange. It expects to raise money through advertising and through its updated career site, which will match its experts with jobs.

It’s unclear what Stack Exchange is valued at, but the company is clearly on a roll. If Quora, the darling of Silicon Valley, is worth an estimated $300 million or more, Stack Exchange, which is bigger according to Alexa and Compete, is likely worth more. And with its latest funding, it’s showing no signs of letting up.

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Opinionaided CEO Dan Kurani said the support is a testament to the engagement and interactivity Opinionaded has shown. He said there have been 50 million responses to 600,000 questions on the iOS app since it began last year. Kurani won’t say how many users he has, but that’s still a pretty impressive amount of activity in a Q&A app.

Opinionaided won’t be mistaken for Quora or Stack Overflow anytime soon. Though users can ask more serious questions, the app elicits more lightweight opinion-type queries because of its simple and open approach. Users can pose any question in more than 20 categories. Respondents can then give a thumbs up, thumbs down or neutral vote as well as add an answer. At times, it can feel like a Hot-or-Not poll if you answer questions in the “attractiveness” category. But where the app stands out is that the response level is extremely high and immediate. Kurani said he originally hoped to get 10 responses for each question but it’s not uncommon for questions to receive dozens of up/down votes and comments within minutes. The answers are sometimes more of the opinion variety, but the immediacy is striking. That’s not always the case with other answer sites, where many queries go untouched or there’s a lag before responses come in.

A lot of that is the app’s fast polling mechanism and Opinionaided’s ability to serve up a steady stream of questions to users. The fact that the app is mobile also helps create a lot of activity because it’s simple and easy to use for a couple of minutes at a time. Opinionaided plays on people’s compulsive nature and their desire to help, but Kurani said it’s not just a mindless voting app. The site returns solid answers and lets users reward good responses with stars, which help their reputation and improves the quality of answers. It also leads to more interaction among users, who are able to communicate around questions and shared interests. That’s where the value of Opinionaided seems to be heading: not in necessarily finding specific answers but getting quick general opinion feedback and building a community around questions.

Kurani said there is room in the Q&A space for a more immediate and casual feedback system. He likens the service in some ways to a structured data Twitter, which he said could open up business opportunities. The company could allow brands to ask questions about their products and gather insights for a fee. Research firms could use the data for sentiment analysis. There’s still a ways to go before the app is regarded with the same respect accorded Quora and Stack Overflow, but the early results show that Q&A services can foster a lot of engagement if they’re mobile, simple and addictive.

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Q&A sites are grabbing the spotlight thanks in part to the emergence of Silicon Valley darling Quora, which has become a destination for many tech luminaries and could be worth $300 million. But the genre is still hampered by a lot of bad answers and unanswered questions. Taking a somewhat different tack from Quora is New York start-up Stack Overflow, which has been growing rapidly by focusing on specific content niches.

Stack Overflow, which was originally spun out of developer Joel Spolsky’s Fog Creek Software, reported last month that it more doubled its unique visitors last year from 7 million to 16.6 million, and in the last month, reached 19 million users to crack Quantcast’s list of top 300 sites. The company says its success stems from creating an expert community in which few questions go unanswered, and virtually all answers are of fairly high quality.

Started as a forum for programmers, Stack Overflow has blossomed into a broader network with 43 Q&A subject areas available now under the umbrella of sites known as Stack Exchange. Funded by by an all-star team of investors — including Union Square Ventures, Ron Conway, Hunch.com CEO Chris Dixon and former Flickr founder Caterina Fake — the site has grown from three full-time staff to 27 employees, occupying a floor downtown near the New York Stock Exchange. In addition to growing its Q&A business, the site is also poised to change the job-search game as it updates its career site to help mate its growing community of experts with jobs.

Founder and CEO Spolsky said in an interview that the secret to Stack Overflow’s success has been its push for high-quality content and its decision to segment the service into well-defined verticals. By limiting the domains in which questions can be asked and stocking the existing sites with knowledgeable users, it helps focus the Q&A process, making it less of a free for all, he said. That’s one of the problems faced by many other sites: Questions are all over the place and many don’t get answered because they don’t get routed to the right people.

Stack Overflow’s limited approached has helped the site boast an impressive answer rate of more than 80 percent, and in some vertical subject areas, well over 90 percent. Unlike other Q&A sites, Stack Overflow polices its questions aggressively, weeding out queries that lead to subjective answers or hard-to-quantify answers. The goal is to address questions that have a clear answer, Spolsky said. Community managers and members can vote to close down questions that aren’t appropriate or they can try to edit them into shape.

Stack Overflow boasts about 760,000 users who contribute to the site and is very serious about building a core community of experts. By creating channels around a specific domain and rewarding the best contributors with reputation points, Stack Overflow looks to foster a community of smart users who can bring a lot of shared knowledge to bear on a question.

“If you go to ask a question about physics, you don’t go out to a football stadium and shout out ‘Who can answer my question about physics?,” said Spolsky. “What you’re going to do is go to a university physics department and try and find someone to help you there and our idea is to build those departments.”

Newbies can wander in, but the site is driven by a critical mass of knowledgeable users, Spolsky said. To that end, the site has eschewed social networking conventions like letting users follow each other, the way Quora does. It also lets people sign in with fake names. “It all comes down to: Do you know the answer?” Spolsky said.

Stack Exchange, which covers a variety of non-technical topics including photography, cooking and English, is now growing faster than Stack Overflow as it reaches into new areas. The network is now up to 1.5 million monthly users and grew by 51 percent in December. But while it opened up with Stack Exchange, the company has applied its quality control on that process as well. In an open voting system called Area 51, Stack Overflow takes submissions and votes on potential new sites. It requires more than 200 users to commit to the new subject area to ensure that it has enough experts when it goes into beta. Stack Exchange is now adding a new site a week and is looking at all manner of subject areas in which some kind of domain expertise can be established.

Stack Overflow gets its revenues from advertising and was actually profitable last year before its big push with Stack Exchange. But Spolsky sees a bigger opportunity to leverage and help its community of experts. The site is about to relaunch its Careers site, which will expand its programming job listings to other subject areas, helping its experts in different fields find jobs and contract work. The idea is to help the community leverage their passion into better jobs, while getting a small cut of the action. And it encourages more involvement from members, who can point to their work on Stack Overflow as a kind of portfolio.

“We’ve always thought that if you can get a group of experts together there are business opportunities around that where everyone can benefit,” Spolsky said, who will be sharing more about the career site on the upcoming Launch conference.

Spolsky believes the emergence of good question and answer sites can also help combat the rise of content farms. Stack Overflow recently announced it would partner with search engine Blekko to use its community of users to help improve programming- and tech-related searches. But Spolsky believes Stack Overflow can also replace a lot of the spammy content with expert-driven answers.

“This is the next thing,” he said. “After search and social, it’s questions and answers.”

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