Type of site
|Question & Answer|
|Owner||Stack Exchange Inc.|
|Created by||Jeff Atwood and Joel Spolsky|
|Launched||September 2009 (relaunched in January 2011)|
|158 (November 2014)[update]|
Stack Exchange is a network of question and answer websites on diverse topics in many different fields, each site covering a specific topic, where questions, answers, and users are subject to a reputation award process. The sites are modeled after Stack Overflow, a forum for computer programming questions that was the original site in this network. The reputation system is designed to allow the sites to be self-moderating.
In 2008, Jeff Atwood and Joel Spolsky created Stack Overflow, a question-and-answer Web site for computer programming questions, which they described as an alternative to the programmer forum Experts-Exchange. In 2009, they started additional sites based on the Stack Overflow model: Server Fault for questions related to system administration and Super User for questions from computer "power users".
In September 2009, Spolsky's company Fog Creek Software released a beta version of the Stack Exchange 1.0 platform as a way for third parties to create their own communities based on the software behind Stack Overflow, with monthly fees. This white label service was not successful, with few customers and slowly growing communities.
In May 2010, Stack Overflow (as its own new company) raised $6 million in venture capital from Union Square Ventures and other investors, and it switched its focus to developing new sites for answering questions on specific subjects,
Stack Exchange 2.0. Users vote on new site topics in a staging area called "Area51", where algorithms determine which suggested site topics have critical mass and should be created. In November 2010, Stack Exchange site topics in "beta testing" included physics, math, and writing. Stack Exchange publicly launched in January 2011 with 33 websites; it had 27 employees and 1.5 million users at the time, and it included advertising. At that time, it was compared to Quora, founded in 2009, which similarly specializes in expert answers. Other competing sites include WikiAnswers and Yahoo! Answers.
In February 2011, Stack Overflow released an associated job board called Careers 2.0, charging fees to recruiters for access. In March 2011, Stack Overflow raised $12 million in additional venture funding, and the company renamed itself to Stack Exchange, Inc. It is based in Manhattan, New York City. In February 2012, Atwood left the company.
The primary purpose of each Stack Exchange site is to enable users to post questions and answer them. Users can vote on both answers and questions, and through this process users earn reputation points, a form of gamification. This voting system was compared to Digg when the Stack Exchange platform was first released. Users receive privileges by collecting reputation points, ranging from the ability to vote and comment on questions and answers to the ability to moderate many aspects of the site. Due to the prominence of Stack Exchange profiles in web search results and the Careers 2.0 board, users may have reason to game the system. Along with posting questions and answers, users can add comments to them and edit text written by others. Each Stack Exchange site has a "meta" section where users can settle disputes, in the style of MetaFilter's "MetaTalk" forum, because the self-moderation system for questions and answers can lead to significant arguments.
All user-generated content (questions and answers) posted on the Stack Exchange Network is copyright by the contributor and licensed to Stack Exchange under the Creative Commons Attribution Share Alike (CC-BY-SA) license. 
Stack Exchange uses IIS and MS SQL servers, and the ASP.NET framework, from a single code base for every Stack Exchange site. (Except Area51, which runs off a fork of the SO code base.) Blogs run under WordPress. The team also notably uses Redis, HAProxy and Elasticsearch.
Stack Exchange tries to stay up to date with the newest technologies from Microsoft usually using the latest releases of any given framework. The code is primarily written in C# ASP.NET-MVC using the Razor View Engine. The preferred IDE is Visual Studio and the data layers uses Dapper for data access.
Site creation process
- Discussion: The Stack Exchange meta site should provide a forum for discussing potential new ideas labeled a future Stack Exchange site.
- Proposal: A public proposal must be drafted and posted so that any member of the community can discuss the proposal and vote on it. This allows a collaborative proposal to emerge over time. The proposal must address these four key issues:
- the topic of the website
- the targeted audience
- forty exemplary questions, upvoted at least 10 times from the community
- sixty followers from the community
- Commitment: 200 users interested in the new site are asked to formally commit and support the site by actively participating and contributing to it.
- Private Beta: If the concept receives 100% commitment, the site enters the private beta phase, where committed members begin actively using the site and publicizing it.
- Public Beta: The site is open to the public for a long period. This allows the creators to ensure that the site reaches critical mass before it is fully launched.
- Graduation: The site is evaluated on multiple criteria such as the number of answered questions, new questions per day, and registered users. If it meets these criteria and is deemed "sustainable", it is granted a “graduation” and fully launched.
Censorship attempt by CipherCloud
On 18 April 2013 CipherCloud issued DMCA takedown notices in an attempt to block discussion of possible weaknesses of their encryption algorithm. The Stack Exchange Crypto group discussion on the algorithm  was censored, but it was later restored without pictures.
- "Legal". Stack Overflow. Stack Exchange. 2010-06-08. Retrieved 2012-01-02.
- Mager, Andrew (September 27, 2009). "Find the answer to anything with StackExchange". The Web Life. ZDNet. Retrieved December 16, 2012.
- Swartz, Jon (January 24, 2011). "Q&A websites like Quora and Stack Exchange take off". USA Today. Retrieved December 16, 2012.
- "stackexchange.com Site Overview". Alexa. 2014-07-05. Retrieved 2014-07-05.
- Atwood, Jeff (May 17, 2009). "A Theory of Moderation". Stack Exchange Blog. Retrieved December 16, 2012.
- Perez, Sarah (July 8, 2010). "With Debut of Web Apps Q&A Site, Stack Exchange Perfects Automated Site Launch Process". ReadWriteWeb. Retrieved December 16, 2012.
- Clarke, Jason (August 20, 2009). "Super User - question and answer site for power users". DownloadSquad. AOL. Retrieved December 16, 2012.
- Oshiro, Dana (October 12, 2009). "StackOverflow Shares its Mojo: White Label Q&A for All". ReadWriteWeb. Retrieved January 1, 2011.
- Kirkpatrick, Marshall (May 4, 2010). "All-Star Team Backs StackOverflow to Go Beyond Programming Questions". ReadWriteWeb. Retrieved December 16, 2012.
- Keller, Jared (November 18, 2010). "Stack Overflow's Crowdsourcing Model Guarantees Success". The Atlantic. Retrieved December 16, 2012.
- Jeffries, Adrienne (January 25, 2011). "Forget Quora, New York’s Stack Overflow Is Killing It". BetaBeat. Retrieved December 30, 2012.
- Jenna Wortham (February 6, 2011). "The Answers Are Out There, and New Q. and A. Sites Dig Them Up". New York Times. Retrieved December 31, 2012.
- Needleman, Rafe (February 23, 2011). "Stack Exchange launches programmer recruiting site". CNet. Retrieved December 16, 2012.
- Ha, Anthony (March 9, 2011). "Q&A startup Stack Overflow gets new name, more funding". VentureBeat. Reuters. Retrieved December 16, 2012.
- Kim, Ryan (February 16, 2011). "Stack Overflow Rides Experts & Order to Q&A Success". GigaOM. Retrieved December 30, 2012.
- Finley, Klint (July 5, 2012). "Stack Overflow Man Remakes Net One Answer at a Time". Enterprise. Wired. Retrieved December 16, 2012.
- "FAQ: What is Reputation?". Stack Overflow. Retrieved 19 January 2010.
- Ha, Anthony (May 4, 2010). "Stack Overflow raises $6M to take its Q&A model beyond programming". Deals. VentureBeat. Retrieved December 31, 2012.
- Popper, Ben (December 7, 2011). "Conquering the CHAOS of Online Community at Stack Exchange". BetaBeat. Retrieved December 16, 2012.
- Carroll, Sean (January 13, 2011). "Physics Stack Exchange". Cosmic Variance. Discover Magazine. Retrieved December 31, 2012.
- Popper, Ben (December 9, 2011). "Stack Exchange Growing 40 Percent a Month, Gaming Vertical Up 250 Percent". BetaBeat. Retrieved December 31, 2012.
- Singel, Ryan (September 20, 2012). "Open Season on Patents Starts Thursday, Thanks to Crowdsourced Platform". Threat Level. Wired. Retrieved December 31, 2012.
- "Legal — Terms of Service". Stack Exchange. December 11, 2014. Retrieved December 21, 2014.
- Craver, Nick (22 November 2013). "What it takes to run Stack Overflow". Retrieved 2 October 2014.
- "Stack Meta". Stack Meta.
- Sewak, M.; et al. (18 May 2010). "Finding a Growth Business Model at Stack Overflow, Inc.". Stanford CasePublisher (Stanford University School of Engineering). Rev. July 20, 2010 (2010-204-1): 31. 204-2010-1. Retrieved 23 May 2014.
- blunders (2012). "Answer to question: Interested in starting Q&A section on Stack Exchange". Appcelerator. Retrieved 23 May 2014.
- "FAQ - Area 51 - Stack Exchange". Stack Exchange, inc. 2014. Retrieved 30 June 2014.
- "CipherCloud used DMCA Takedown on StackExchange discussion of the cryptography".
- "CipherCloud Invokes DMCA To Block Discussions of Its Crypto System".
- "How is CipherCloud doing homomorphic encryption".