
Description: JS.do is an online JavaScript playground and code sharing platform. It allows you to easily test JavaScript code, see visualizations, create snippets to share with others, and collaborate on code.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: CodePen is an online code editor and front-end web development environment. It allows developers to easily create and share HTML, CSS, and JavaScript code snippets and projects.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API