UseResponse - Open-source, self-hosted customer feedback software, live chat and helpdesk system that you can install on your server. Organize documentation using knowledge base and get feedback from social networks with centralized system
Stack Overflow for Teams - Everything you love about Stack Overflow in a private space.
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
Stack Overflow Trends - Current programming and technology trends by Stack Overflow
Survicate - Collect feedback on your website and find out more about your visitors.
Community Questions for Confluence - Keep questions and answers in one place with an engaging, community-driven Q&A discussion forum, powered by Confluence