SolidJS

SolidJS is an open-source reactive JavaScript UI framework created by Ryan Carniato in 2018, combining the developer experience of React with the performance characteristics of compiled frameworks, using fine-grained reactivity instead of virtual DOM diffing to achieve exceptional rendering performance, consistently benchmarking as the fastest JavaScript UI framework with the smallest bundle size, adopted by companies including Netlify, Cloudflare, and Vercel for production applications and gaining rapid adoption with over thirty thousand GitHub stars. The fine-grained reactivity system tracks dependencies at the signal level rather than the component level, meaning that when state changes, only the specific DOM nodes that depend on that state are updated, without re-rendering entire component trees or using virtual DOM reconciliation, resulting in performance that approaches vanilla JavaScript while maintaining a declarative component model. The JSX-based component API feels familiar to React developers, with components defined as functions that return JSX, props accessed through destructuring, and hooks-like patterns through createSignal, createEffect, createMemo, and createStore primitives, but with fundamentally different execution model where components run only once during initial render, with effects tracking reactive dependencies automatically. The signals primitive represents a reactive value with getter and setter, effects automatically re-run when their signal dependencies change, memos provide cached derived values, and stores enable deep reactivity for objects and arrays through proxy-based tracking. The server-side rendering support provides streaming, hydration, and island-based client hydration. The SolidStart meta-framework provides routing, SSR, and deployment presets. The compilation strategy produces optimized JavaScript with minimal runtime overhead. Designed for performance-focused frontend developers.