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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Stack Exchange

Stack Exchange is a fast-growing network of 84 [and counting] question and answer sites on diverse topics from software programming to cooking to photography and gaming.

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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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Mamute

A tool for community driven questions and answers. Includes voting, mark as solved, tags and many more.

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Scoold

Scoold is inspired by StackOverflow and implements most of its features. You can ask and answer questions, upvote and downvote posts, earn badges and reputation.

Free Open Source Web Self-Hosted

Coordino

Coordino allows you to create a question and answer system for you and your users to enjoy.

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Answers

Answers is the place to go to ask questions and receive answers from the community at large on any topic. Connect with people who know the answers to your questions...

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Askalot

Askalot is a next generation CQA (Community Question and Answer) system.

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Fixoncloud

Interaction platform for programming enthusiasts, learners, and experts to solve problems. Fast and inexpensive solutions to your programming problems. People with no...

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LampCMS

LampCMS is an full-featured Open Source Question and Answers web program written in PHP with deep integration with Facebook, Twitter, Google, Linked-IN, Tumblr and...

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