List of Clone open source software like stackoverflow to host on your website?

If you are looking to host feature like stackoverflow on your own website then it would definitly upset you coz open source version of stackoverflow is not available.

Stack Overflow is a question and answer site for professional and enthusiast programmers. It is a privately held website, the flagship site of the Stack Exchange Network, created in 2008 by Jeff Atwood and Joel Spolsky.

Stack Exchange has released an updated, feature-complete version of the Stack Overflow engine which is now available for enterprise use. You can compare the feature out here.
https://stackoverflow.com/teams/pricing

So What are the best alternatives to Stack Overflow which you can host on your website and similar to Stack Overflow? Here are some of the those as follows:

Rajesh Kumar
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