I really like markdown, very readable in the state that it is in before it is converted to whatever else. I also like reStructuredText.
Outputting to different formats is important I guess, however, I would say that most real reading that is done is done in html. With that said, I love beautiful documentation, one because I enjoy what I am reading to look nice, if given the choice and two, from a marketing perspective, our docs look like they came from Redhat in the early 2000's (read old and outdated) Take Ceph's install docs where they are using http://sphinx-doc.org to create them. http://ceph.com/docs/master/install/ Very nice looking, well laid out and useful. I don't think the concern about about formats was as important as usability. Tracy
