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

HyperTest is a no-code test automation tool that regresses all your APIs by auto-generating integration tests using your network traffic, also giving a way to reproduce these failures inside actual user-journeys.

Burp or Burp Suite is a set of tools used for penetration testing of web applications. It is developed by a company named Portswigger who make freely available a Web Security Academy which has a range of lessons on penetration testing.

Easy-to-use website monitoring and uptime monitoring service in one

Datadog is a cloud-based monitoring and analytics platform that provides observability and security for cloud-scale applications

The open-source status page system