The Apache JMeter™ application is open source software, a 100% pure Java application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions.

Hoppscotch is an open-source API development ecosystem that helps you create and test your API requests saving precious time in development.

Checks web UI for browser compatibility (Compliance with Can I Use?)

Automation Test Reporting. OSS, Language & Framework agnostic

GIPHY CAPTURE is the best way to create GIFs on your Mac. Simple, powerful, free, and easy enough for pretty much everyone and even a few small mammals.

A screenshot/screenvideo tool! Also allows you to do basic alterations to the screenshots (arrows, blur, ...)