Questions answered by this recipe
How can I get simultaneous edits to work on systems that can't call the Unix diff3 command?
The phpmerge.phpΔ script replaces the merge function distributed with PmWiki with a version that doesn't require an external diff3 program. To use this script, simply copy it to the cookbook/ directory and add the following lines to local/config.php:
This will cause PmWiki to attempt to merge simultaneous edits, denoting conflicting sections with <<<<<<< and >>>>>>> as appropriate.
See discussion at SimultaneousEdits-Talk.