Apache RocketMQ 
Apache RocketMQ is a distributed messaging and streaming platform with low latency, high performance and reliability, trillion-level capacity and flexible scalability.
It offers a variety of features:
- Pub/Sub messaging model
- Scheduled message delivery
- Message retroactivity by time or offset
- Log hub for streaming
- Big data integration
- Reliable FIFO and strict ordered messaging in the same queue
- Efficient pull&push consumption model
- Million-level message accumulation capacity in a single queue
- Multiple messaging protocols like JMS and OpenMessaging
- Flexible distributed scale-out deployment architecture
- Lightning-fast batch message exchange system
- Various message filter mechanics such as SQL and Tag
- Docker images for isolated testing and cloud isolated clusters
- Feature-rich administrative dashboard for configuration, metrics and monitoring
Learn it & Contact us
- Mailing Lists: https://rocketmq.apache.org/about/contact/
- Home: https://rocketmq.apache.org
- Docs: https://rocketmq.apache.org/docs/quick-start/
- Issues: https://github.com/apache/rocketmq/issues
- Ask: https://stackoverflow.com/questions/tagged/rocketmq
- Slack: https://rocketmq-invite-automation.herokuapp.com/
Apache RocketMQ Community
Contributing
We always welcome new contributions, whether for trivial cleanups, big new features or other material rewards, more details see here.
License
Apache License, Version 2.0 Copyright (C) Apache Software Foundation