Coreact

Coreact is an open-source JavaScript library designed for building user interfaces with a focus on core reactive state management. It provides a minimal runtime and a small set of primitives that let developers compose UIs from declarative components while keeping the surface area limited.

At its core, Coreact relies on signals, effects, and memos. Signals represent observable values; effects run in response to changes and trigger updates to the component tree; memos derive computed values without re-running all dependent computations. Components are functions that return a description of the UI, and they subscribe to signals to reflect current state.

The rendering model emphasizes incremental updates and batch processing to minimize DOM work. Coreact supports direct DOM rendering or integration with a virtual-DOM layer for larger apps. It also includes a lightweight store system for sharing state across components and supports asynchronous data through suspensible resources, enabling simple loading and error handling patterns.

Coreact originated from a collaborative project released in 2023 and is maintained by an open community under an MIT license. It aims to provide a small, fast alternative to larger frameworks, with a focus on predictable updates and ease of composition. The ecosystem is smaller than those of React or Vue, but tooling and examples exist for modern bundlers and TypeScript usage.