* [sitespeed.io v41.2.0](https://github.com/sitespeedio/sitespeed.io) – Comprehensive web performance tool for measuring, monitoring, and optimizing website speed.

* [Obs.js 0.3.0](https://github.com/csswizardry/Obs.js) – Context-aware performance utilities that detect connection and battery status to adapt site behavior and add CSS classes.

* [analyze-css v2.4.40](https://github.com/macbre/analyze-css) – CSS selectors complexity and performance analyzer providing detailed metrics and offender reports.