The problem with OOo is the file format is really a zip compressed group of files (try changing the file extension to .zip or .7z). This makes it difficult to do diffs on.
I've been looking at LaTex and DocBook, but establishing a style template to use is quite difficult. This is the hard part all the tutorials gloss over.
So basically I've given up on getting meaningful diffs from documentation. It gets checked in as binary blobs.
