JavaScript is a great language for writing and testing quick apps with user interaction

• Demo
• Source

• A browser (e.g., Firefox or Chrome)
• A text editor (e.g., VS Code or Notepad++, or Chrome)

• No downloads required - almost every computer already has a browser
• No languages, tooling, or versions - browsers already run JavaScript
• Code using functional, declarative, object-oriented, imperative, and event-driven paradigms
• Built-in features for user input
• Easy-to-style with free, pre-made styles (hosted in CDN)

• Bootstrap 4

• More App Examples