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

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

Test, scrape, generate, and automate without the pain and expense of hosting your own headless browsers.

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).

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.

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