xdiff extension creates and applies patches to both text and binary files.
To use xdiff, you will need libxdiff installed, available on the libxdiff homepage http://www.xmailserver.org/xdiff-lib.html.
Note: You'll need at least libxdiff 0.7 for these functions to be aware of memory_limit.
xdiff is currently available through PECL http://pecl.php.net/package/xdiff.
If PEAR is available on your *nix-like system you can use the pear installer to install the xdiff extension, by the following command: pear -v install xdiff.
You can always download the tar.gz package and install xdiff by hand: