We are using Jive for all of our internal documentation which works really well for us. For deep documentation, both new document requests and document updates are submitted using a built-in "Ideas" feature. "Ideas" can include plain text, links, images, or videos, and can be submitted by anyone in the company. With this information, we can create a new document, save it in Jive, and then respond to the "Idea" with a "The document is done and here's the link to it" comment. For quick fire Q&A, we've created a page in Jive that uses built-in "Questions" and "Answers" features, again, accessible to anyone in the company. Jive's search feature is pretty robust (keyword-indexes anything you add to it without having to create tags, though you can add tags if you want).