From the homepage:
JanusGraph is a scalable graph database optimized for storing and querying graphs containing hundreds of billions of vertices and edges distributed across a multi-machine cluster.
JanusGraph is a transactional database that can support thousands of concurrent users executing complex graph traversals in real time.
In addition, JanusGraph provides the following features:
- Elastic and linear scalability for a growing data and user base.
- Data distribution and replication for performance and fault tolerance.
- Multi-datacenter high availability and hot backups.
- Support for ACID and eventual consistency.
- Support for various storage backends:
- Support for global graph data analytics, reporting, and ETL through integration with big data platforms:
- Support for geo, numeric range, and full-text search via:
- Native integration with the TinkerPop graph stack:
- Open source under the Apache 2 license.
Follow the Getting Started with JanusGraph guide for a step-by-step introduction.
Supported by Google, IBM and Hortonworks, among others.
Three good reasons to pay attention to JanusGraph early and often.