For those more detailed screen recordings like demos as well as bugs. Has a built in editor.

Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

Best "simple" screen capturing app (Mac and Windows) because it creates animated gifs that attach to bugs easily. Simple because it works a lot like snippy to capture screen areas

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.

SeleniumBase Case Plans is Test Case Management Software that uses Markdown tables for displaying test plans directly in GitHub (and other source code management systems that support Markdown format).

Gatling is a powerful open-source load testing solution that integrates with your development pipeline. It includes a web recorder and colorful reports.