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

Website type	Knowledge market Question and answer
Owner	Prosus N.V.
Creator	Jeff Atwood Joel Spolsky
Website	stackexchange.com
Commercial	Yes
Registration	Yes
Launched	September 2009 (2009-09) (relaunched in January 2011)
Content license	User contributions under CC BY-SA 2.5, 3.0, and 4.0

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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.

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.

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.

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