Mercurial is a great tool for managing versions of (collaborative) documents: it allows to
track modifications (and their authors) that are done to a directory. With this tool old
versions can always be retrieved, and it is possible to find who added/deleted something
and why (for example in a Dropbox shared folder). Mercurial is also very useful even if we
are not working with someone, since we can still track changes that we do in a project.
I have written a short note to explain the usage of Mercurial with applications to paper writing in sciences; you can find it on the Sciences page, or you can access it directly here: