I've been writing all my documentation in AsciiDoc for the past few years, and I love it! As another commenter mentioned, it's even compatible with markdown. I

I've been writing all my documentation in AsciiDoc for the past few years, and I love it! As another commenter mentioned, it's even compatible with markdown. I previously used Microsoft Word for all documentation, but the lack of human-readable diffs in source control was a PITA, and some features are just much better in IDEs that Word (e.g. search and replace with regex).