In Firefox, the Telemetry system collects various measures of Firefox performance, hardware, usage and customizations and submit it to Mozilla. This article provides pointers to documentation.
Note: Every new data collection in Firefox now needs a data collection review from a data collection peer. Just set the data-review? flag for one of the data stewards. We try to reply within a business day.
Adding new Telemetry probes is now documented in the Mozilla Source Tree docs.
To discover more Telemetry tools and documentation, visit the Telemetry portal.
The Telemetry team is there to help with any problems. You can reach us via: