Best Knowledge Base plugin and great support!

I bought the Pro Max version and use it in combination with the Docy theme from the same developers. It is a great setup geared towards an optimal reading experience. The combination of footnotes, next/prev buttons, glossary, and front-end collaboration features are unique. No other Knowlegde Base, Wiki or documentation plugin comes close.

On top of that they have a very responsive support team that is willing to help and really looks into your specific situation to come up with a solution. They release fixes and new features frequently.