Fed up with the absence of a decent diff engine I’ve started working on my own. And it’s available through a web interface. It does a decent job on even long (200 pages) documents, with no sync failures … at least none I’ve found so far :)
The engine has been designed to work with odt files and pdfs, but it at the moment the interface only works for web pages (and text extracts which are pasted in). Comparison times are relatively slow (compare gpl to agpl takes about 8 seconds), but hopefully that can be improved with a bit of effort. As I usually don’t care about format, no effort has been expended in preserving formatting.
Old URL: http://www.gnu.org/licenses/gpl.html
To see the difference between the gpl and the agpl.