Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
Community Questions for Confluence - Keep questions and answers in one place with an engaging, community-driven Q&A discussion forum, powered by Confluence
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Stack Overflow for Teams - Everything you love about Stack Overflow in a private space.
Askalot - Askalot is a next generation CQA (Community Question and Answer) system.
Discourse - Discourse is an open source discussion platform built for the next decade of the Internet.