The Generic Diff Format (GDIFF) is a proposal to W3C for a data format that is used to express the difference between two data streams, very often two different versions of a file.
The GDIFF is defined as a set of commands that, when applied to an old version of a file, produces the new version of a file.
Using GDIFF, it is possible to produce differences between files that are potentially much smaller in size than either the old or new version.
Read more about the GDIFF specification at the
this XPS version
of the specification. Also, be sure to have a look at
this blog post
that I wrote about the GDIFF library.
How to Use the Library
section for information on how to use the GDIFF library in your code.