I'm planing to move project documentation for a fairly big software project from using Microsoft Word files with manual versioning in the filename to storing it in the source version control system. This would all be the type of documentation written by the developer team, release notes, upgrade instructions and administration guidelines so the format can be fairly complicated. Ideally it needs to be possible to publish it as both pdf and html.
At the moment I'm considering LaTeX or DocBook.
Are there any other formats to consider?
What are the pros and cons of these formatting languages?
Just to add what I've opted on doing (pretty much based on the accepted answer):
I'm going with DocBook as most of the developers on the project are quite well versed in webby languages such as XSL, XML and HTML so DocBook should seem familiar.
Also because I discovered it is quite well supported to automatically build the docs along with the project code using Maven (removing the hassle around publishing the docs was the whole purpose of this).