RethinkDB

RethinkDB is an open-source, distributed JSON document database designed to power real-time applications with ease. It features built-in changefeeds that automatically push updates to connected clients ideal for live dashboards, chat apps, and IoT systems. Released under the Apache 2.0 license and now a Linux Foundation project, RethinkDB offers a modern query language (ReQL), horizontal scalability, and a developer-friendly ecosystem.As a specialized alternative in the real-time database space, it competes with systems like MongoDB, Apache Cassandra, CouchDB, and KeyDB, offering a unique edge for applications requiring streaming updates.

Key features include:

• Real-time Changefeeds: Subscriptions to live query updates with minimal setup
• ReQL Query Language: Rich, chainable queries with joins, grouping, and map/reduce
• Distributed Architecture: Automatic sharding and replication with fault tolerance
• Web-based Admin UI: Visual cluster monitoring and management
• Multi-language Drivers: Native support for Python, JavaScript, Ruby, Java, and more

Use cases include:

• Real-time dashboards and analytics
• Collaborative or chat applications
• Multiplayer gaming backends
• IoT and sensor data streaming
• Applications needing live updates without polling