GDIFF

GDIFF (Generic Diff) is a binary format for representing "diffs" of what has changed in a file since a previous version. It was released as a format specification submitted in 1997 to the W3C as a note, to be published in their site but not explicitly endorsed by that organization.

Identification
A GDIFF file starts with the hex bytes  followed by a one-byte version number.

Specifications

 * GDIFF spec, in W3C site

Programming libraries

 * gdiff package

Other links

 * Man page