solid-js

Solid is a declarative JavaScript library for creating user interfaces that compiles templates to real DOM nodes and updates them with fine-grained reactions. Unlike React's virtual DOM diffing approach, Solid compiles JSX at build time into optimized DOM operations that update only the exact elements and attributes that change, without re-executing component functions after initial render. This produces exceptional performance benchmarks, often matching or exceeding hand-optimized vanilla JavaScript. Solid uses signals, memos, and effects as reactive primitives — signals hold values, memos derive computed values, and effects run side effects when their dependencies change. Components in Solid run only once during creation, with the reactive system handling all subsequent updates. This means there are no rules of hooks, no stale closure issues, and no unnecessary re-renders. Solid supports JSX with some differences from React, including native spread attributes, show/for control flow components, and portals. The framework provides Solid Router for client-side routing and SolidStart as a meta-framework for full-stack applications with SSR support.