Question2Answer - A Q&A site helps an online community to share knowledge.
Kajabi - Kajabi is the only Knowledge Commerce platform today with everything you need to market, sell, and deliver your knowledge online.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Tendenci - Tendenci - The Open Source AMS is a cloud-based all-in-one management SaaS solution for Non-profits and Associations.
Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
ChamberMaster - ChamberMaster is a member management software.