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

Voiden is a developer-first API client with local storage, Git-integrated, all based on markdown + offline support.

Playwright enables reliable end-to-end testing for modern web apps.

A test framework for testing bash scripts

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.

Simulate APIs, integrations, and environments at enterprise scale.