Robot Framework is a generic open source automation framework. It can be used for test automation and robotic process automation (RPA).

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

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

Loader.io is a free load testing service that allows you to stress test your web-apps & apis with thousands of concurrent connections.

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).

Anyone on your team can load test with instant playback, an easy-to-use interface, and real browsers for reliable data.