Cliqz is a privacy-oriented fork of Mozilla Firefox. It includes its own unique anti-tracking system, an integrated ad-blocker, anti-phishing measures, and an embedded search engine. In "Tracking the Trackers", a paper published in the Proceedings of the 25th International Conference on the World Wide Web, Cliqz engineers compared their anti-tracking system with Disconnect and Ad-Block Plus, concluding that their system was a measurable improvement. Cliqz uses its built-in search engine to provide suggestions in the address bar as users begin to type a query. This engine uses a local index of popular pages to provide results without sending search information to remote servers. As users browse pages, they are added to this local index so that they can later be found with a search. In addition to providing users with better privacy protections, this system for address bar completion is also faster than using an external service. Users may submit anonymous browsing data to improve the Cliqz default index by opting into their "Human Web" system. Cliqz installers are available for Windows and macOS desktops, as well as Android and iOS devices. Source code for the Cliqz browser and a number of their server-side services are available on GitHub under free software licenses.