Best Free Message-Oriented Middleware of 2024

RabbitMQ is lightweight, portable, and easy to use on the premises or in the cloud. It supports multiple messaging protocols. RabbitMQ can both be deployed in distributed or federated configurations to meet high availability and scale requirements.

Solace is a specialist in Event-Driven-Architecture (EDA), with two decades of experience providing enterprises with highly reliable, robust and scalable data movement technology based on the publish & subscribe (pub/sub) pattern. Solace technology enables the real-time data flow behind many of the conveniences you take for granted every day such as immediate loyalty rewards from your credit card, the weather data delivered to your mobile phone, real-time airplane movements on the ground and in the air, and timely inventory updates to some of your favourite department stores and grocery chains, not to mention that Solace technology also powers many of the world's leading stock exchanges and betting houses. Aside from rock solid technology, stellar customer support is one of the biggest reasons customers select Solace, and stick with them.

HiveMQ is the most trusted enterprise MQTT platform, purpose-built to connect anything via MQTT, communicate reliably, and control IoT data. The platform can be deployed anywhere, on-premise or in the cloud, giving developers the flexibility and freedom they need to evolve as their IoT deployment grows. HiveMQ is reliable under real-world stress, scales without limits, and provides enterprise-grade security to meet the needs of organizations at any stage of digital transformation. The extensible platform provides seamless connectivity to the leading data streaming, databases, and data analytics platforms, plus offers a custom SDK for a perfect fit in any stack.

Ably is a pub/sub messaging platform that is enterprise-ready. Our platform makes it simple to quickly design, ship, and seamlessly scale critical realtime functionality directly to end-users. Every day, we deliver billions in real-time messages to millions of users and thousands of companies. We power the apps people, companies, and enterprises rely on every day. This includes Lightspeed System's realtime platform for device management for more than seven million school-owned devices, Vitac’s live captioning for 100s to millions of multilingual viewers for events such as the Olympic Games, Split's realtime feature flagging, which allows for one trillion feature flags each month. We are the only pub/sub platform that offers a complete suite of integrated services. This includes showing drivers' GPS locations on a home-delivery app and loading the most recent score when opening sports apps. It also handles reconnections when switching networks.

Azure SignalR Service makes it easy to add real-time communication to your web application. You don't need to be a real time communications expert! Real-time features are not something you have to manage. SignalR Service is fully managed, making it easy to add real time communication functionality to your application. You don't have to worry about hosting, scaling, or load balancing. Everything is handled automatically. Azure offers everything! Integrate with Azure Functions, Azure App Service and Azure Active Directory. Azure Storage, Azure Analytics, Power BI. IoT, Cognitive Services. Machine Learning. SignalR Service Premium Tier allows you to leverage enterprise capabilities like auto-scaling and higher SLA. It also supports Azure Availability Zone support and rate limiting. Integrate with other monitoring solutions or send advanced metrics to Azure Monitor.

StreamNative redefines the streaming infrastructure by integrating Kafka MQ and other protocols into a unified platform that provides unparalleled flexibility and efficiency to modern data processing requirements. StreamNative is a unified platform that adapts to diverse streaming and messaging requirements in a microservices environment. StreamNative's comprehensive and intelligent approach to streaming and messaging empowers organizations to navigate with efficiency and agility the complexity and scalability in the modern data ecosystem. Apache Pulsar’s unique architecture decouples message storage from the message serving layer, resulting in a cloud-native data streaming platform. Scalable and elastic, allowing it to adapt to changing business needs and event traffic. Scale up to millions of topics using architecture that decouples computing from storage.

Middleware Observability & management software for Messaging, event processing, and Streaming Across Hybrid Clouds (MESH). - 360 degree situational awareness® with complete observability of Integration MESH - Manage configuration, administration and deployment in a secure manner and automate them. - Track and trace transactions, messages, and flows - Collect data, monitor performance, and benchmark it meshIQ provides granular controls for managing configurations in the MESH, reducing downtime and allowing quick recovery after outages. It allows you to search, browse, track and trace messages in order to detect bottlenecks, speed up root cause analysis, and detect bottlenecks. Unlocks integration blackbox for visibility across MESH infrastructure in order to visualize, analyse, report and predict. Delivers the capability to trigger automated action based on predefined criteria or intelligent AI/ML actions.

Responsive apps keep developers motivated and users engaged. With the DataStax Astra streaming service platform, you can meet these ever-increasing demands. DataStax Astra Streaming, powered by Apache Pulsar, is a cloud-native messaging platform and event streaming platform. Astra Streaming lets you build streaming applications on top a multi-cloud, elastically scalable and event streaming platform. Apache Pulsar is the next-generation event streaming platform that powers Astra Streaming. It provides a unified solution to streaming, queuing and stream processing. Astra Streaming complements Astra DB. Astra Streaming allows existing Astra DB users to easily create real-time data pipelines from and to their Astra DB instances. Astra Streaming allows you to avoid vendor lock-in by deploying on any major public cloud (AWS, GCP or Azure) compatible with open source Apache Pulsar.

Eclipse Mosquitto (EPL/EDL licensed), is an open-source message broker that implements MQTT versions 5.0, 3.1 and 3.1.1. Mosquitto is a lightweight message broker that can be used on any device, from single board computers with low power to full servers. The MQTT protocol is a lightweight way to send messages using a publish/subscribe method. This makes it ideal for Internet of Things messages, such as low-power sensors or mobile devices like phones, embedded computers or Microcontrollers. The Mosquitto Project also provides a C Library for implementing MQTT Clients, as well as the very popular command line MQTT client mosquitto_pub.

CoreDX DDS provides an easy-to-use Inter-Process Communication library (IPC), which is cross-platform and cross-language. CoreDX DDS has low overhead and high performance, with low latencies to support real-time controls and high message throughputs to support high bandwidth data. CoreDX DDS offers secure, robust and flexible data communications. CoreDX DDS, based on open standards to ensure interoperability and viability over the long term, is the preferred IPC of a wide range of distributed software applications, from mobile games, consumer electronic devices, and health care applications to complex DoD systems and robots in space. CoreDX DDS is popular among programmers because it's easy to use, has many features that are difficult to implement manually, and offers unique features not found in any other IPC library. CoreDX DDS offers programmers features such as integrated end-toend security, data storage and filtering, data presentation and event notification options.