Kurrent (formerly EventStoreDB)

Kurrent, formerly known as EventStoreDB, is an operational event sourcing database purpose-built for building event-driven applications that need to store, query, and replay immutable streams of domain events. The platform provides a fundamentally different data storage paradigm compared to traditional CRUD databases: instead of overwriting current state, Kurrent appends every state-changing event to an append-only log, enabling complete audit trails, time-travel queries to any point in history, and automatic rebuilding of application state through event replay. Key technical features include distributed ACID transactions at the stream level, projections that allow real-time querying of event data using JavaScript, subscription-based event delivery for building reactive CQRS and event sourcing architectures, and gossip-based clustering for high availability with automatic failover. The database supports both gRPC and HTTP APIs, integrates with popular messaging systems, and provides connectors for building read models and sagas. Kurrent Cloud offers fully managed deployments on AWS and Azure with automated scaling, backup, and monitoring. The platform is used by organizations in financial services, healthcare, e-commerce, and logistics for use cases including payment processing, inventory management, audit compliance, real-time analytics, and microservices communication. As the rebranded evolution of EventStoreDB, Kurrent continues the open-source tradition under the EventStoreDB community edition while offering commercial KurrentDB editions with advanced features like multi-node clustering, continuous backups, and enterprise support. The project has over 5,500 GitHub stars and maintains an active community of developers building event-sourced systems worldwide.