Question & answer websites (like Stack Overflow) are great platforms for enabling communities to share knowledge and help each other.
Although they are kinda similar-in-function with the forum applications (check 9 Widely-Used And Free Forum Softwares), the main focus is finding the (best) answers.
Here are 5 free and open source or hosted platforms to create your own question-answer website:
Question2Answer
Question2Answer is an application that is built with PHP-MySQL that has a points-based reputation system.
Users can comment into any questions and they can be tagged.
It can be totally styled with CSS and has an admin interface to manage the whole application.
QSQA
QSQA enables anyone to instantly create a full-featured question-answer community where users can earn point/badges for their contribution.
It is written in Python and powered by the Django application framework.














