Установка и настройка
PHP Manual

Требования

To use xdiff, you will need libxdiff installed, available on the libxdiff homepage » http://www.xmailserver.org/xdiff-lib.html.

Замечание:

You'll need at least libxdiff 0.7 for these functions to be aware of memory_limit.


Установка и настройка
PHP Manual