Create Wiki sites and blogs, even with PDF export options, using XWiki
XWiki is a free platform, an “engine”, that will let you create Wikies and blogs, complete with a comment system, authentication, extensions , scripting, and more. XWiki can prove very useful in team work, web sites and intranets. Wiki syntax of course is supported, and backups.
A nice feature is the ability to import Office documents, data from CSV files and native XWiki content. The management of all these content types is powerful and flexible. Search is also powerful, allowing also for wildcards.
As you can guess, XWiki helps you also to create groups and users under several roles and permissions. Statistics are available and can be really helpful. Regarding the interface, you can have templates, skins, custom styles, menus. Wiki pages can be saved as HTML, PDF, XML, RTF and ODT formats.
XWiki is a powerful free platform you can try especially if you are interested in team work.