Selenium automates browsers. That's it! What you do with that power is entirely up to you.

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

Browser and Mobile Automation Test Framework for Node.js

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.

Free & OpenSource REST API Testing Tool for all levels in a Test Pyramid

Jest is a delightful JavaScript Testing Framework with a focus on simplicity.