We're using LaTeX and SVN. Since LaTeX documents are just text files, it plays well with version control, unlike some binary or partially-binary formats.

You get all the advantages (and disadvantages, admittedly) of version control you're used to from using it with your code.

LaTeX takes a little setting up (to define your own styles/class), but once you've done so it's very good - you can concentrate solely on the content rather than its presentation (rather than being tempted to constantly tweak as you are with WYSIWYG), yet still get a slick, professional-looking PDF document at the end.

Wiki-like tool for writing specifications and documentation
I am not sure if this holds true everywhere, but here in Germany you only get two attemps at getting your PhD. I am currently wondering at which point it counts towards those two attempts. If I were to start a position and quit during the first few weeks, would it still count?
