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
wikiHow - wikiHow is a wiki based collaboration to build the world’s largest, highest quality how to manual.
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.
Blurtit - Blurtit is a Q&A website. You can ask a question or answer on any question.
Survicate - Collect feedback on your website and find out more about your visitors.
AllAnswered - Your Team's Collective Brain All-In-One Knowledge Management System Wiki + Q&A + Workflow + AI