This page contain informations about building quora clone, stackoverflow clone, or any other questions ansewrs website with elgg open source social networking software.
You can build stackoveflow clone or quora clone with free or paid clone scripts. Other options are plugins for popular CMS systems like Wordpress, Drupal, Joomla and similar. When you choose specialized software for building QA website you get all functionalities out of the box. Problem with these scripts is updating with bug and security fixes. Developers often abandon scripts when they loose interest or don't get enough earning from maintaining script. You can search for QA scripts on google and you'll find that there are many abandoned scripts. If script powering your website become full of bugs and security holes you will have to move to other software and this is not a small job. Building website with popular open source CMS systems gives you certain level of security regarding regular updates. Yes, CMS plugins can get abandoned but it is incomparably easier to update plugin than whole system.
I recommend building QA site with Elgg. Advantage of Elgg over Wordpress, Drupal, Joomla and similar open source software is base purpose of Elgg. Elgg is community framework, tool for building community websites where all users participate in content creation. CMS (Content Management System) software primary purpose is for building websites with small number of content creators and larger number of content consumers. Typical CMS example is newspaper website, small number of writers and many readers. QA sites are community sites where every member have option to participate in asking and replying, this is why Elgg requires much less work to get to goal of creating questions answers website.
There are two QA plugins for elgg, elgg-questons and answers plugin. Questions plugin is more closer to look and fill of Quora and Facebook questions. It uses elgg core "like" functionality for voting. Answers plugin is stackoverflow clone on top of Elgg. Interface is the same like on Stack Exchange site network. You can choose which plugin is better for your needs.
Video demonstrates using Elgg 1.8 with elgg-questions plugin.