Definition: "RO.js" refers to a JavaScript library used in web applications for rapid prototyping and testing purposes, often used with Node.js and React. Definition: "RO.js" stands for Rapid Object-Oriented JavaScript, which emphasizes object-oriented programming over traditional imperative languages (like JavaScript) while maintaining the speed of modern browser-based frameworks. It is particularly useful for creating prototypes or small-scale interactive applications, especially in web development. The library provides a simple way to create and manage objects using a single type, making it easy to write dynamic, scalable, and maintainable code.