The document describes WebBox, a platform for storing and sharing personal data across multiple devices and cloud services. WebBox aims to support modern data needs with security, versatility, and adoptability. It uses a PostgreSQL database, object store, and versions data with transactional integrity. WebBox provides APIs for web and mobile applications to access user data stores via an HTTP/WebSocket interface with token-based authentication. Examples provided include a data editor, real-time chat app, and Twitter harvester. The document also discusses enabling communication between WebBox instances.