For a long time Mozilla’s JS team and others have been using https://arewefastyet.com to track the JS engine performance against various benchmarks.
In the last little while, there’s been work moving those benchmarks to another continuous integration system and we have the metrics in Mozilla’s Perfherder. This rewrite will focus on using the new generated data.
If you’re curious on the details about the UI refresh please visit this document. Feel free to add feedback. Stay tuned for an update next month.