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

JUnit is an open source testing framework designed to facilitate unit testing in Java.

Simulate APIs, integrations, and environments at enterprise scale.

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

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

NUnit is a unit-testing framework for all .Net languages.