
Description: HTMLPen.com is a free online HTML editor that allows you to write, edit and preview HTML code in real-time. It has a clean interface with syntax highlighting and other handy coding features.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: jsFiddle is an online code editor that allows users to create, edit, debug and share HTML, CSS and JavaScript code snippets. It's useful for testing code, sharing examples, and prototyping web apps quickly.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API