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

Puppeteer is a Node.js library which provides a high-level API to control Chrome/Chromium over the DevTools Protocol.

Don’t just observe. Take action. The only app monitoring platform built for developers that gets to the root cause for every issue.

Design, debug, and test APIs locally or in the cloud

API Testing Platform that automatically generates unit test cases with dependency mocks from API calls

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.