EMQX is a message oriented middleware platform built around an MQTT broker for connecting devices and streaming real time data to the cloud and AI systems. Developed by EMQ, the broker supports MQTT versions 3.1, 3.1.1, and 5.0, and is designed to handle millions of concurrent device connections. A built in rule engine and more than 50 native integrations, including Apache Kafka, InfluxDB, and PostgreSQL, let teams route and transform device data without writing custom code.

EMQX is offered as a pay as you go Serverless cloud plan with a free usage quota, a Dedicated Flex cloud plan starting at 234 dollars per month, a Bring Your Own Cloud option, and self managed Enterprise software for on premises or hybrid deployment. An open source edition also remains available for self hosted use.

HiveMQ is an enterprise MQTT message broker platform built for connecting Internet of Things devices, industrial systems, and connected products at scale. Founded in Germany, the company provides a broker that fully supports the MQTT 3.1.1 and 5.0 protocols with a masterless cluster architecture for high availability. HiveMQ Data Hub adds policy based validation for incoming data, and enterprise extensions connect the broker to systems such as Apache Kafka and Snowflake.

HiveMQ is available as HiveMQ Cloud, a fully managed service with a free Serverless tier, and as self managed software that can run on premises or in any cloud environment. Self managed pricing starts at 299 dollars per month, and an open source Community Edition is also available under the Apache 2.0 license for smaller deployments and development.

CloudAMQP is a managed hosting service for RabbitMQ and LavinMQ message brokers, operated by the Swedish company 84codes AB. It provisions, monitors, and scales message queue clusters on behalf of customers across shared and dedicated cluster types, removing the need to install and operate broker servers directly.

Plans range from a free shared multi-tenant instance to dedicated single- and multi-node clusters sized for high-throughput production workloads. CloudAMQP supports the AMQP, MQTT, STOMP, and WebSocket protocols, provides a monitoring dashboard with alerting, and can be deployed across AWS, Google Cloud, Microsoft Azure, and DigitalOcean in more than 129 regions. Its infrastructure is SOC 2, GDPR, and HIPAA compliant, with customers including Mozilla, Docker, and Heroku.

Confluent Cloud is a fully managed, cloud-native service for Apache Kafka, built and operated by the original creators of Apache Kafka. It runs on Confluent's proprietary Kora engine and handles cluster provisioning, scaling, patching, and upgrades so teams can stream and process event data in real time without operating Kafka brokers themselves.

The service uses consumption-based pricing across Basic, Standard, Enterprise, and Freight cluster tiers, with a free Basic tier that scales to zero when idle. Confluent Cloud includes more than 120 pre-built connectors, a schema registry, Apache Flink and ksqlDB stream processing, and Cluster Linking for bridging to existing Kafka deployments, plus support for Avro, Protobuf, and JSON Schema formats. Confluent is headquartered in Mountain View, California.

ZeroMQ, also written as ØMQ, is an open-source networking library that provides messaging sockets without requiring a central message broker or daemon process. Applications link the library directly and use it to build custom messaging patterns such as publish-subscribe, request-reply, and push-pull over transports including TCP, in-process, inter-process, and multicast.

Because it runs as an embedded library rather than a hosted server, ZeroMQ works on Linux, Windows, and macOS and offers bindings for more than twenty programming languages, including C, C++, Python, Java, and Go. It is free to use under LGPL licensing terms, and is used by companies such as Microsoft, Spotify, and Samsung to build low-latency, distributed, and concurrent systems.

Apache Pulsar is an open-source, distributed messaging and streaming platform originally created at Yahoo and now maintained as a top-level Apache Software Foundation project. It combines traditional message queuing with stream processing in a single system, separating stateless brokers from an Apache BookKeeper storage layer so brokers can be added or removed without reshuffling data.

Pulsar supports multi-tenancy, geo-replication across clusters, and topic-level acknowledgment models similar to both Kafka and RabbitMQ. It offers official client libraries for Java, Go, Python, C++, Node.js, and C#, plus Pulsar Functions for lightweight serverless processing. Because it is licensed under Apache License 2.0, Pulsar can be self-hosted on premises or in any cloud at no licensing cost, with commercial managed offerings available from third-party vendors.

TIBCO Enterprise Message Service is a messaging middleware product that implements the Java Message Service (Jakarta Messaging) specification, letting applications exchange messages through queues and topics. It is part of the TIBCO Messaging product family and also interoperates with TIBCO FTL and TIBCO Rendezvous, making it a common backbone for service-oriented and event-driven integration across heterogeneous platforms and programming languages.

TIBCO offers a free Community Edition limited to small-scale use, alongside a paid Enterprise Edition with fault tolerance, load balancing, and full support. EMS can be installed on premises or deployed in Docker and Kubernetes containers on AWS, Google Cloud, or Azure. Pricing for the Enterprise Edition is custom and quote based, provided directly by TIBCO sales.

Solace PubSub+ is an event streaming and management platform built around the PubSub+ Event Broker, which moves data between applications, cloud services, and devices in real time. The broker supports multiple protocols and APIs, including AMQP, JMS, MQTT, REST, and WebSocket, plus a native bridge to Apache Kafka. It is available as software, a cloud service, or a hardware appliance, and these can be combined into a single event mesh across clouds and data centers.

Solace is used in financial services, manufacturing, retail, and transportation for high-volume event processing, and several major investment banks and telecom providers run production workloads on it. The platform also includes PubSub+ Event Portal for event governance and design. A free, production-ready software edition and a 30-day cloud trial are both available, with paid plans for larger deployments handled through direct sales.

NATS is a high-performance, lightweight, open-source messaging system for building distributed and cloud-native applications. Released under the Apache 2.0 license and stewarded by Synadia as a Cloud Native Computing Foundation incubating project, NATS runs as a single small binary and supports publish/subscribe, request-reply, and persistent streaming through its JetStream engine. It also includes built-in key-value and object storage.

NATS is designed for low, sub-millisecond latency and can scale from a single process to global deployments using leaf nodes and superclusters for edge and multi-region topologies. Official client libraries exist for Go, Rust, Python, Java, JavaScript, C#, C, and Ruby, among others. Because NATS is free to self-host, Synadia separately sells Synadia Cloud, a managed NATS hosting service with paid tiers and a 14-day trial.

Google Cloud Pub/Sub is an asynchronous, fully managed messaging service that decouples services producing events from services processing them. It supports both push-based delivery to HTTP webhooks and pull-based retrieval, with typical end-to-end latency around 100 milliseconds. Pub/Sub is designed for real-time event distribution, data ingestion pipelines, database change replication, and building organization-wide event buses.

The service offers at-least-once delivery by default, with optional exactly-once delivery and message ordering by key. Other features include dead-letter topics, message filtering, and schema validation. Pub/Sub integrates tightly with Dataflow, BigQuery, Cloud Storage, and Cloud Functions, and provides client libraries for languages including Java, Python, Go, and Node.js. A free monthly allowance covers the first 10 GB of throughput.