The DiffService service is used to show the differences between the page versions. The configuration of this service is found in wiki-service/src/main/resources/conf/portal/configuration.xml:

Sample configuration:

<component>

    <key>org.exoplatform.wiki.service.diff.DiffService</key>

    <type>org.exoplatform.wiki.service.diff.DiffService</type>

</component>