We've implemented plain old MediaWiki in our division. It serves as a document and guidance distribution point to the wider corporate public, as well as an scratch pad for internal procedures and process. Due to the general lack of fine-grained access control and segmentation, we stood up two instances: one for the "public" site without authentication for read-only access (and mediawiki accounts for division members only to edit content) and another one for the "private" site with HTTP authentication for the wiki root.