Stack Exchange

Not to be confused with Stock Exchange.
This article is about the network of collaborative Q&A sites. For the first site in the network, see Stack Overflow.
"Super User" redirects here. For a user account with special privileges, see superuser.

Stack Exchange Network
Type of site
OwnerProsus N.V.
Created by
URLstackexchange.com Edit this at Wikidata
CommercialYes
RegistrationYes
LaunchedSeptember 2009; 15 years ago (2009-09)[1]
(relaunched in January 2011)[2]
Content license
User contributions under CC BY-SA 2.5, 3.0, and 4.0[3][4]

Stack Exchange is a network of question-and-answer (Q&A) websites on topics in diverse fields, each site covering a specific topic, where questions, answers, and users are subject to a reputation award process. The reputation system allows the sites to be self-moderating.[5] As of March 2023, the three most actively viewed sites in the network are Stack Overflow (which focuses on computer programming), Unix & Linux, and Mathematics.[6]

All sites in the network are modeled after the initial site Stack Overflow which was created by Jeff Atwood and Joel Spolsky in 2008. Further Q&A sites in the network are established, defined, and eventually – if found relevant – brought to creation by registered users through a special site named Area 51.[7][8]

User contributions since May 2, 2018 are licensed under Creative Commons Attribution-ShareAlike 4.0 International. Older content, contributed while the site used the Creative Commons Attribution-ShareAlike 3.0 Unported license or the earlier Creative Commons Attribution-ShareAlike 2.5 Unported license, remains licensed under the license in force at the time it was contributed.[4][3][9]

In June 2021, Prosus acquired Stack Overflow for $1.8 billion, its first complete acquisition in the area of educational technology.[10]

  1. ^ Cite error: The named reference zdnet was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference usatoday was invoked but never defined (see the help page).
  3. ^ a b "Stack Exchange and Stack Overflow are moving to CC BY-SA 4.0". meta.stackexchange.com. Retrieved September 18, 2019.
  4. ^ a b "An Update On Creative Commons Licensing". Retrieved March 3, 2020.
  5. ^ Atwood, Jeff (May 17, 2009). "A Theory of Moderation". Stack Exchange Blog. Archived from the original on May 15, 2017. Retrieved December 16, 2012.
  6. ^ "All Sites – Stack Exchange". stackexchange.com. Archived from the original on November 22, 2019. Retrieved March 25, 2023.
  7. ^ "All Sites". Stack Exchange. Archived from the original on November 22, 2019. Retrieved April 1, 2017.
  8. ^ "FAQ – Area 51 – Stack Exchange". Stack Exchange, Inc. 2014. Archived from the original on August 7, 2020. Retrieved June 30, 2014.
  9. ^ "Legal — Terms of Service". Stack Exchange. December 11, 2014. Archived from the original on January 3, 2012. Retrieved December 21, 2014.
  10. ^ Dummett, Ben (June 2, 2021). "WSJ News Exclusive | Stack Overflow Sold to Tech Giant Prosus for $1.8 Billion". Wall Street Journal. ISSN 0099-9660. Archived from the original on October 29, 2021. Retrieved June 3, 2021.