Vue.js 3.0 is the latest major version of the Vue.js JavaScript framework for building user interfaces. Here's an overview of Vue.js 3.0:

1. Composition API:

• Vue.js 3 introduces the Composition API, a new way to organize and reuse logic in components. It allows developers to encapsulate related functionality in composition functions, making it more modular and maintainable.

2. Reactivity System:

• The reactivity system in Vue.js 3 has been improved for better performance. It uses a proxy-based system that provides fine-grained reactivity, making it more efficient than the Object.defineProperty-based system used in Vue.js 2.

3. Teleport:

• Vue.js 3 introduces the Teleport feature, which allows developers to move a child component to a different part of the DOM tree. This is useful for creating advanced UI structures and overlays.

4. Fragments:

• Vue.js 3 supports fragments, allowing components to return multiple root nodes. This simplifies component structure and eliminates the need for unnecessary wrapper elements.

5. Suspense:

• The Suspense feature enables better handling of asynchronous operations in components. It allows components to suspend rendering until a condition is met, improving the user experience during data fetching.

6. Custom Renderer API:

• Vue.js 3 provides a more accessible and flexible Custom Renderer API, making it easier for developers to create custom renderers for different environments, such as server-side rendering or native mobile applications.

7. Multiple v-models:

• Vue.js 3 allows multiple v-model bindings on a single component, providing more flexibility in handling different input sources or managing multiple pieces of state.

8. Global Mounting API:

• The Global Mounting API simplifies the process of mounting Vue.js instances to elements, providing a more straightforward approach to integrating Vue.js with existing projects.

9. Improved TypeScript Support:

• Vue.js 3 comes with enhanced TypeScript support, making it even more attractive for developers who prefer statically-typed languages.

10. Performance Improvements:

• Vue.js 3 is designed with performance in mind, featuring optimizations that contribute to faster rendering and improved runtime efficiency.

11. Ecosystem Compatibility:

• While introducing new features, Vue.js 3 maintains compatibility with existing Vue.js 2 components, allowing for a smooth migration path for projects already using Vue.js.

12. Official Vue.js CLI 5:

• Vue.js 3 is complemented by the Vue.js CLI 5, providing a powerful and efficient development environment with features like instant prototyping, scaffolding, and more.

As a progressive framework, Vue.js continues to evolve, and version 3.0 brings significant improvements, making it a compelling choice for developers building modern and reactive user interfaces.