PsySH - A runtime developer console, interactive debugger and REPL for PHP.
SmallDevTools - Handy developer tools with a delightful interface
Jupyter - Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages. Ready to get started? Try it in your browser Install the Notebook.
Google Open Source - All of Googles open source projects under a single umbrella
RunKit - RunKit notebooks are interactive javascript playgrounds connected to a complete node environment right in your browser. Every npm module pre-installed.
whatdevsneed - This is whatdevsneed.