In MS Word, there's a nice feature called "track changes" that allows the program to track edits. This is useful when collaborating with others because you can enable various visualization modes where it's easy to see what others have changed.
I'm in the process of editing a large amount of documentation written in LaTeX and stored in a subversion repository. I'd like to be able to easily highlight changes between different revisions. Does anyone know of a good system for taking a pair of revisions of a LaTeX file and automatically generating word-level (not just line-level) diff markup (i.e. one color or style for unchanged text, another color for added content, another for deleted, etc.)?