I've seen MediaWikia and Confluence used successfully. It does require culture . . . but I've noticed that more people use the friendlier tool and that we have

I've seen MediaWikia and Confluence used successfully. It does require culture . . . but I've noticed that more people use the friendlier tool and that we have a lot more documentation with Confluence. The MediaWiki stuff was okay, but clumsy. Other tools I've seen used with success generally have the characteristics of being lightweight, not too complicated, and having a relatively frictionless interface for making small changes (e.g., "press an Edit button and start typing"). I've been in a culture that desperately wanted to do documentation, but the tool that management forced people to use was SharePoint, and it was horrible (search functionality that never worked, very bad response time, very difficult to link or move documents, and worst of all a policy to delete "unused" SharePoint sites after a while . . . the result being that important engineering documentation was irretrievably destroyed). PMs loved the busywork that SharePoint created for them. I wound up putting all of our documentation into source control and snapshotting it to SharePoint periodically. This made me unpopular with the PMs, but I'm pretty sure the documents are still there, a decade later. So tooling doesn't matter, unless the tooling stinks badly enough.