ArrayShift is a question/answer site built to emulate the core functionality of the StackOverflow.com site and the StackExchange platform. Originally built as a fantasy site for Lullabot’s Do It With Drupal conference in December 2009, the installation profile is capable of bootstrapping and configuring the initial site.

It currently implements a reasonable subset of the site’s functionality, but is incomplete and far from bug-free. It has rough edges that need to be smoothed out and functionality that needs to be finished in other contrib modules before this package could be considered a full feature-clone of Stack Overflow, or before it could be considered ready-for-use by site builders who do not already know Drupal well. A TODO.txt will be coming shortly.

PHP StackOverflow Clone

Qwench is a PHP/mySQL based StackOverflow clone.

Features
1. Allow users to post questions and answers
2. Points system similar to StackOverflow
3. Ability to post an article as a knowledge-base (for corporates)
4. Ability to lock site to registered users only
5. Clean CSS layout
6. Works in all major browsers

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

Features

• A Knowledge Platform
• User Rewards
• Tagging
• Site Administration
• Total Control
• Remote Authentication
• Source Code
• Selfhosted Solution
• Free Year of Support

OpenMind enables you to build an online community with your customers and partners, allowing you to:

• Find out what features and improvements your customers as a whole would value most

Engage in an online discussion with your users to gain deeper insights into their needs

• Communicate upcoming releases, closing the loop on customer feedback – your customers can see exactly which suggestions became committed features of a future release based upon community feedback
• Gain deeper insights into specific targeted topic areas through user surveys
• Allow customers to engage in online discussion with each other and with you via online forums