Stencil

Stencil is a compiler for building reusable, scalable component libraries that generate small, blazing fast Web Components running natively in any browser. Created by the Ionic team, Stencil combines the best concepts from popular frameworks including React virtual DOM, Angular dependency injection, Vue async rendering, and Svelte static compilation, without being a framework itself. Components authored in TypeScript compile to standard Custom Elements that work across React, Vue, Angular, Svelte, and vanilla JavaScript without wrappers. The compiler performs ahead-of-time optimization, tree-shaking, and lazy-loading automatically, distributing each component as a separate chunk. The Decorators API uses TypeScript decorators for component metadata, reactive properties with change detection, watchers, and lifecycle hooks. JSX rendering with a Virtual DOM layer provides efficient diffing. Built-in support for server-side rendering, prerendering, and hydration enables SEO-friendly static site generation. The distribution system generates framework-specific wrappers that provide idiomatic APIs for React, Angular, and Vue consumers. Ionic Framework, with millions of weekly npm downloads, is built entirely with Stencil. The Ionic Appflow platform provides cloud-native build and deployment. Used by Apple, Amazon, Mastercard, Volkswagen, Target, Burger King, Panera Bread, IBM, Porsche, and Credit Suisse. Version 4 is the latest major release with improved TypeScript 5 support, Custom Elements everywhere, and reduced runtime size. Open source under the MIT license with over 12,200 GitHub stars.