via wptavern.com => original post link
WordPress Playground, an experimental project that uses WebAssembly (WASM) to run WordPress in the browser, makes it possible for users to quickly test plugins and themes without having to set up a local development environment.
Ordinarily, testing a plugin or theme with Playground requires visiting playground.wordpress.net, which will instantly create a real WordPress instance with admin access without having to install PHP, MySQL, or Apache. It runs inside the browser using a SQLite database. Adding a plugin or theme to the instance is as easy as appending the slug to the URL when creating the test site:
https://playground.wordpress.net/?plugin=gutenberg