Stack Exchange

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.^[1] As of March 2023,^[update] the three most actively-viewed sites in the network are Stack Overflow (which focuses on computer programming), Unix & Linux, and Mathematics.^[2]

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.^[3]^[4]

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.^[5]^[6]^[7]

In June 2021, Prosus acquired Stack Overflow for $1.8 billion, its first complete acquisition in the area of educational technology.^[8]

^ Atwood, Jeff (May 17, 2009). "A Theory of Moderation". Stack Exchange Blog. Archived from the original on May 15, 2017. Retrieved December 16, 2012.
^ "All Sites – Stack Exchange". stackexchange.com. Archived from the original on November 22, 2019. Retrieved March 25, 2023.
^ "All Sites". Stack Exchange. Archived from the original on November 22, 2019. Retrieved April 1, 2017.
^ "FAQ – Area 51 – Stack Exchange". Stack Exchange, Inc. 2014. Archived from the original on August 7, 2020. Retrieved June 30, 2014.
^ "An Update On Creative Commons Licensing". Retrieved March 3, 2020.
^ "Stack Exchange and Stack Overflow are moving to CC BY-SA 4.0". meta.stackexchange.com. Retrieved September 18, 2019.
^ "Legal — Terms of Service". Stack Exchange. December 11, 2014. Archived from the original on January 3, 2012. Retrieved December 21, 2014.
^ 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.

[1] Atwood, Jeff (May 17, 2009). "A Theory of Moderation". Stack Exchange Blog. Archived from the original on May 15, 2017. Retrieved December 16, 2012.

[2] "All Sites – Stack Exchange". stackexchange.com. Archived from the original on November 22, 2019. Retrieved March 25, 2023.

[Traffic-3] "All Sites". Stack Exchange. Archived from the original on November 22, 2019. Retrieved April 1, 2017.

[Area51-4] "FAQ – Area 51 – Stack Exchange". Stack Exchange, Inc. 2014. Archived from the original on August 7, 2020. Retrieved June 30, 2014.

[license_split_3.0_4.0-5] "An Update On Creative Commons Licensing". Retrieved March 3, 2020.

[license_change-6] "Stack Exchange and Stack Overflow are moving to CC BY-SA 4.0". meta.stackexchange.com. Retrieved September 18, 2019.

[7] "Legal — Terms of Service". Stack Exchange. December 11, 2014. Archived from the original on January 3, 2012. Retrieved December 21, 2014.

[8] 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.

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