|Headquarters||Mountain View, California|
|Key people||Adam D'Angelo (CEO)|
|Alexa rank||817 (June 2013[update])|
|Type of site||Knowledge markets|
Quora is a question-and-answer website created, edited and organized by its community of users. The company was founded in June 2009, and the website was made available to the public on June 21, 2010.
Quora aggregates questions and answers to topics. Users can collaborate by editing questions and suggesting edits to other users' answers. Quora's main competitors are social bookmarking sites like reddit, social networking sites like ChaCha, and numerous question and answer websites.
Quora was co-founded by two former Facebook employees, Adam D'Angelo and Charlie Cheever. D'Angelo resigned from his position at Facebook in January 2010 to create Quora. He said that he and Cheever were inspired to create Quora because "we thought that Q & A is one of those areas on the Internet where there are a lot of sites, but no one had come along and built something that was really good yet." Quora's base of users grew quickly in December 2010.
Quora had an estimated 500,000 registered users, as of January 2011. In June 2011, Quora redesigned its website, in order to make information discovery and navigation easier. Some noted that the redesigned site had definite similarities to Wikipedia. Quora released an official iPhone app on September 29, 2011  and an official Android app on September 5, 2012.
Quora requires users to register with their real names rather than a screen name. Quora users may also link/ log-in with their Quora accounts with their Twitter and Facebook accounts. Quora users can upvote or downvote answers. They can also suggest edits to existing answers provided by other users. The Quora community includes some well-known people, such as Steve Case, Marc Andreesen, Dustin Moskovitz, Jimmy Wales, Justin Trudeau and Ashton Kutcher  The largest group of Quora users is located in Silicon Valley, followed by New York City. Almost 40% of its users are Indians as of May 2013.
Quora uses Pylons and Comet for its backend and Ubuntu Linux as its operating system with MySQL as its database. It also uses Git and memcached. Quora uses Nginx as a reverse proxy server and HAProxy for load balancing. Quora has developed its own algorithm for ranking answers, which works similar to PageRank. Quora uses Amazon Elastic Compute Cloud technology to host the servers that run its website. In August 2011, Quora switched its infrastructure's Python implementation from CPython to PyPy, in order to improve response time.
In August 2012, Blogger Ivan Kirigin pointed out that it was possible for acquaintances to see his activity including which questions he had looked at. In response, Quora stopped showing questions views in feed later that month.  By default, Quora exposes its users' profiles, including their personal names, to search engines.
In March 2010, Quora received funding in the amount of $11 million from Benchmark Capital, valuing the start-up at $86 million. Quora's valuation was rumored to be more than $1 billion in February 2011, and the privately held company possibly turned down an acquisition offer of $300 million, according to Business Insider.
In May 2012, Quora raised $50 million in Series B funds, valuing the company at over $400 million and bringing their total funding to $61 million. The co-founder D'Angelo, who owns 0.8% of Facebook stock, also invested $20 million of his own money in the B round. (same source)
According to Robert Scoble, Quora succeeded in combining attributes of Twitter, Facebook, Google Wave and similar websites that are based on a system of users voting up content. Scoble later criticized Quora for being a "horrid service for blogging," and although a decent question and answer website, not substantially better than competitors. The Daily Telegraph has predicted that Quora will become larger than Twitter. Quora, along with Airbnb and Dropbox, has been named among the next generation of multibillion dollar start-ups by the New York Times.
In 2010 D'Angelo and Cheever were among five named "Smartest Engineer runner-up" in the "smartest people in the tech" article by CNNMoney. They were also both listed in the Inc. Top 30 Under-30 entrepreneurs list of 2011.
- "quora.com". quora.com. Retrieved 2013-04-06.
- "Quora.com Site Info". Alexa Internet. Retrieved 2013-06-16.
- Monday, June 21st, 2010 (2010-06-21). "Quora’s Highly Praised Q&A Service Launches To The Public (And The Real Test Begins)". Techcrunch.com. Retrieved 2013-04-06.
- Wortham, Jenna (March 12, 2010). "Facebook Helps Social Start-Ups Gain Users". New York Times. Retrieved March 29, 2010.
- "Why I Quit My CTO Job At Facebook And Started Quora". Business Insider. Retrieved March 29, 2010.
- "The Mystery Behind Quora". Boston Innovation. Retrieved March 29, 2010.
- Lewenstein, ed. (November 28, 2010). "Quora Signups Explode". Retrieved January 24, 2011.
- Arthur, Charles; Jemima Kiss (5 January 2011). "Quora: the hottest question-and-answer website you've probably never heard of". The Guardian. Retrieved 31 May 2012.
- Friday, June 24th, 2011 (2011-06-24). "techcrunch.com". techcrunch.com. Retrieved 2013-04-06.
- "Announcing Quora for iPhone and iPod touch — Gallimaufry". Quora. Retrieved 2012-02-12.
- "Introducing Quora for Android". Quora. Retrieved 2012-10-05.
- Cutler, Kim-Mai (2012-09-11). "Quora Co-Founder Charlie Cheever Steps Back From Day-To-Day Role At The Company". Text "publisher — TechCrunch" ignored (help)
- "What is Charlie Cheever's status at Quora as of September 11th, 2012?". Quora.
- Tay, Kah Keng (2013-01-23). "Introducing Blogs on Quora". Quora. Retrieved 2013-02-01.
- Constine, Josh (2013-01-23). "Quora Launches Blogging Platform With Mobile Text Editor To Give Every Author A Built-In Audience". TechCrunch. Retrieved 2013-02-01.
- Username*:. "linkedmediagroup.com". linkedmediagroup.com. Retrieved 2013-04-06.
- Dishman, Lydia (2011-01-04). "fastcompany.com". fastcompany.com. Retrieved 2013-04-06.
- Taber, Jane (October 19, 2011). "Quora offers clues as to why Justin Trudeau won't yet seek Liberal helm — The Globe and Mail". The Globe and Mail (Toronto).
- "Quora's New Algorithm for Ranking Answers". ReadWriteWeb. Retrieved March 29, 2010.
- "Quora Signups". ReadWriteWeb. Retrieved March 29, 2010.
- Lohr, Steve (April 22, 2011). "Amazon Malfunction Raises Doubts About Cloud Computing". The New York Times.
- Gaynor, Alex (August 12, 2011). "Quora is now running on PyPy". Quora.
- "This is a bit fucked, Quora". Giantrobotlasers.com. 2012-08-13. Retrieved 2013-04-06.
- "Removing Feed Stories about Views". http://blog.quora.com/. 2012-08-14. Retrieved 2013-05-30.
- "Benchmark Invests at $86 Million Valuation". TechCrunch. Retrieved March 29, 2010.
- "Quora Investor Scoffs At $1 Billion Offer Price". Retrieved July 17, 2012.
- "Get Ready For A Huge Quora Round". Retrieved July 17, 2012.
- "Former Facebook Hands Capitalize on Buzz". Wall Street Journal. Retrieved July 17, 2012. "Quora raised $50 million in a new financing that values it at $400 million, up from a valuation of around $86 million two years ago, said people familiar with the matter. The new financing round is led by Facebook board member Peter Thiel, who invested with his own personal funds", May 15, 2012
- Facebook Alums Push Q&A Site Quora. Wall Street Journal. May 15, 2012.
- "(company): What will Quora do with the $50 million in funding it just received?". Quora. Retrieved 2013-04-06.
- "V.C.’s Answer Yes to Quora". Nytimes.com. March 30, 2010. Retrieved March 29, 2010.
- Baig, Edward C. "Social-networking site Quora has answers to your questions". USA Today. Retrieved March 29, 2010.
- "Is Quora the Next Red-Hot Web Start-Up". Time.com. Retrieved March 29, 2010.
- Yiannopoulos, Milo. "Quora will be bigger than Twitter". London: Telegraph. Retrieved March 29, 2010.
- "Is Quora the biggest blogging innovation in 10 years". Scobleizer. Retrieved March 29, 2010.
- "Why I was wrong about Quora as a blogging service...". Scobleizer. January 30, 2011. Retrieved August 9, 2011.
- Rusli, Evelyn M. (2012-12-13). "The New Start-Ups at Sun Valley". Dealbook.nytimes.com. Retrieved 2013-04-06.
- "CNN 2010 Smartest People in Tech". Money.cnn.com. 2010-07-09. Retrieved 2013-04-06.
- "Top 30 Under 30, 2011". inc.com.
- "Honoree Profiles for C.Cheever, A.D'Angelo, Top 30 Under 30, 2011". inc.com.