What are some alternatives?
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.
Slate API Docs Generator - Create beautiful, intelligent, responsive API documentation.
Doxter - Software for creating, organizing and publishing project documentation
Sandcastle - Sandcastle produces accurate, MSDN style, comprehensive documentation by reflecting over the source...
Confluence - Confluence is content collaboration software that changes how modern teams work