DokuWiki - DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
Notice - Turn your Help Center into an SEO traffic machine.
Banana Dance Wiki/CMS - Free open source software combining the best of wiki and CMS with community building-features.
webcomet - webcomet lets you create and manage FAQs and knowledgebases that are easily published onto your websites.
TiddlyWiki - a non-linear personal web notebook
hagrid - You work really hard to get people to your website.And they have so many things they want to ask!hagrid is a no-code widget, where visitors ask questions and you respond; a user generated FAQ that adds trust and lets you connect with your audience.