Intersect Contribs intersects the contribution history of two users on a Wikimedia project to find which pages have been edited by both of them.
It's useful to discover sockpuppets, double votes and false accounts.
The tool is currently hosted on Wikimedia Tool Labs at the following address: https://intersect-contribs.toolforge.org/
It was previously hosted on Wikimedia Toolserver.
The tool is a simple script written in PHP. The tool directly accesses a replica of the Wikimedia database to fetch the contributions of the users; it also uses the MediaWiki API to obtain information about the namespaces of projects.
You can send any request, bug report, suggestions for improvements or pull request here on GitHub. Alternatively, you can reach me on Meta Wikimedia.
This software is licensed under the GNU General Public License, Version 3.
You can find a copy if it in the LICENSE file.