Manual:$wgExternalDiffEngine/ja

詳細
使用する外部差分エンジンの名前です. 内部エンジンを使用するには false を設定します.

The possible values are:
 * false: wikidiff2 if available, PHP implementation else.
 * wikidiff2: Wikimedia's fast difference engine implemented as a PHP/HHVM module.
 * wikidiff and wikidiff3 are treated as false for backwards compatibility.
 * any other string is treated as a path to external diff executable.

This setting replaces.