Replicache

Replicache is a client-side synchronization framework designed for developers to build real-time, collaborative web applications. It enables instant user interfaces by operating on a local, persistent copy of data in the browser, eliminating the need for constant server roundtrips and progress bars. This architecture supports optimistic UI updates, where changes appear immediately to the user and are then synchronized with the backend in the background. The framework is backend-agnostic, working with most existing backend stacks. It handles complex synchronization challenges such as conflict resolution through server reconciliation, multi-tab usage, and schema migrations. Replicache also provides robust offline support, allowing applications to function seamlessly even when disconnected from the internet and then synchronize changes smoothly once connectivity is restored. After five years of development and use, Replicache is now in maintenance mode, open-sourced, and free to use, with the team shifting focus to a new project called Zero.