Stack Overflow - Community-based Q&A part of the Stack Exchange platform.

FUEL CYCLE by Passenger - Think Passenger builds online platforms that allow brands to connect, create and communicate with key stakeholders.

The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.

Mobilize - Mobilize is a scalable messaging app built for large groups.

Askalot - Askalot is a next generation CQA (Community Question and Answer) system.

Higher Logic - Private, secure online communities that stimulate conversation and ignite engagement.