gURL - gURL is a free, Open Source (GPL) HTTP request generator tool.

Herd Garden - Browser Superpowers for your AI Agents: Automate tasks, extract data, create AI web tools, and manage MCP servers in your browser or across millions of them. Secure, private, and scalable.

Postman - The Collaboration Platform for API Development

puppeteer - Puppeteer is a Node library which provides a high-level API to control headless Chrome or Chromium...

soapUI - SoapUI Pro is one of the most prominent API testing platforms around, allowing developers to quickly prototype the functions of their apps and get them to market with little hassle.

Selenium - Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily, it is for automating web applications for testing purposes, but is certainly not limited to just that.