Stack Exchange

Stack Exchange Network
Type of site
OwnerProsus N.V.
Created by
URLstackexchange.com
CommercialYes
RegistrationYes
LaunchedSeptember 2009 (2009-09)
(relaunched in January 2011)
Content license
User contributions under CC BY-SA 2.5, 3.0, and 4.0

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.