Stack Overflow

stack overflow, part of stack exchange , is a free, community-driven, reputation-based q & a site for computer programmers.

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Question2Answer

A Q&A site helps an online community to share knowledge. No matter what your area of interest, people with questions can get super answers fast. Question2Answer is a popular Q&A solution.

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OSQA

OSQA is the free, open source Q&A system you've been waiting for. Your OSQA site is more than just an FAQ page, it is a full-featured Q&A community.

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AllAnswered

AllAnswered.com is a free hosted service for any community to build their own Stack Overflow-like Q&A board. Check it out to see how easy it is to have your own Stack Overflow.

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Niko

Niko makes it incredibly easy for employees at all levels to share what is on their mind by letting them submit, vote on, and respond to questions, ideas and...

Freemium Web Self-Hosted

Answerbase

Answerbase looks to offer enterprise grade social Q&A to websites of every size, in a web platform that is easy to setup and manage. The platform is built and...

Commercial Web