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. 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.
Type of site | |
|---|---|
| Headquarters | New York City, New York, U.S. |
| Owner | Stack Exchange Inc. |
| Created by | |
| URL | stackexchange |
| Commercial | Yes |
| Registration | Yes |
| Launched | September 2009 (relaunched in January 2011) |
Content license | User contributions under CC BY-SA 2.5, 3.0, and 4.0 |
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 $1.8 billion, its first complete acquisition in the area of educational technology.