List of the Top 11 Free Message-Oriented Middleware in 2025

Sashulin Message Broker (SMB) is an adaptable software messaging solution designed to facilitate communication and information exchange among various applications, systems, and services. Through the use of messaging and transformations, it enables seamless interactions between services that are built on different programming languages and platforms. Developers benefit from SMB's provision of standardized business components, which can be interconnected to construct efficient business process workflows. This streamlined approach empowers developers to concentrate on the essential logic of their applications while leveraging the capabilities of the message broker. Ultimately, SMB enhances the flexibility and efficiency of integrating diverse services in a cohesive manner.

RabbitMQ serves as a nimble messaging solution that can be easily implemented in both on-premises setups and cloud-based environments. Its support for multiple messaging protocols renders it a flexible choice for a variety of applications. Additionally, RabbitMQ can be set up in distributed and federated configurations to meet the needs for high scalability and robust availability. With a large community of users, it is recognized as one of the top open-source message brokers currently available. Companies ranging from T-Mobile to Runtastic utilize RabbitMQ, demonstrating its suitability for both burgeoning startups and established enterprises alike. Moreover, it is designed to work seamlessly across a multitude of operating systems and cloud platforms, providing a rich array of development tools tailored for popular programming languages. Users can take advantage of deployment options including Kubernetes, BOSH, Chef, Docker, and Puppet, which enables smooth integration into their current environments. Developers also have the ability to craft cross-language messaging solutions using a selection of programming languages such as Java, .NET, PHP, Python, JavaScript, Ruby, and Go, thereby broadening its applicability across diverse projects. Ultimately, RabbitMQ’s versatility and compatibility make it an essential tool for modern software development.

Ably stands out as the leading platform for realtime experiences. With more WebSocket connections than any competing pub/sub service, we facilitate connections for over a billion devices each month. Companies rely on us for their essential applications, including chat, notifications, and broadcasts, ensuring that these services run reliably, securely, and at an impressive scale. Our commitment to excellence makes us the preferred choice for businesses seeking to enhance their realtime capabilities.

Solace specializes in Event-Driven Architecture (EDA) and boasts two decades of expertise in delivering highly dependable, robust, and scalable data transfer solutions that utilize the publish & subscribe (pub/sub) model. Their technology facilitates the instantaneous data exchange that underpins many daily conveniences, such as prompt loyalty rewards from credit cards, weather updates on mobile devices, real-time tracking of aircraft on the ground and in flight, as well as timely inventory notifications for popular retail stores and grocery chains. Additionally, the technology developed by Solace is instrumental for numerous leading stock exchanges and betting platforms worldwide. Beyond their reliable technology, exceptional customer service is a significant factor that attracts clients to Solace and fosters long-lasting relationships. The combination of innovative solutions and dedicated support ensures that customers not only choose Solace but also continue to rely on their services over time.

HiveMQ stands out as the most trusted MQTT platform for enterprises, designed specifically to facilitate connections through MQTT, ensure dependable communication, and manage IoT data effectively. Its versatility allows for deployment in various environments, whether on-premise or in the cloud, granting developers the adaptability they require as their IoT projects expand. Known for its reliability even under challenging conditions, HiveMQ scales effortlessly and incorporates enterprise-level security features that cater to organizations at any phase of their digital transformation journey. Furthermore, this flexible platform enables smooth integration with top data streaming services, databases, and analytics tools, while also providing a customizable SDK to seamlessly integrate into any technological ecosystem. As IoT demands continue to evolve, HiveMQ remains a pivotal resource for businesses aiming to leverage cutting-edge technology.

StreamNative revolutionizes the streaming infrastructure landscape by merging Kafka, MQ, and multiple other protocols into a unified platform, providing exceptional flexibility and efficiency that aligns with current data processing needs. This comprehensive solution addresses the diverse requirements of streaming and messaging found within microservices architectures. By offering an integrated and intelligent strategy for both messaging and streaming, StreamNative empowers organizations with the capabilities to tackle the complexities and scalability challenges posed by today’s intricate data ecosystems. Additionally, the unique architecture of Apache Pulsar distinguishes between the message serving and storage components, resulting in a resilient cloud-native data-streaming platform. This design is both scalable and elastic, permitting rapid adaptations to changes in event traffic and shifting business demands, while also scaling to manage millions of topics, thereby ensuring that computation and storage functions remain decoupled for enhanced performance. Ultimately, this pioneering structure positions StreamNative at the forefront of meeting the diverse needs of modern data streaming, while also paving the way for future advancements in the field. Such adaptability and innovation are crucial for organizations aiming to thrive in an era where data management is more critical than ever.

Captivating applications not only engage users but also inspire developers to push the boundaries of innovation. In order to address the increasing demands of today's digital ecosystem, exploring the DataStax Astra Streaming service platform may prove beneficial. This platform, designed for cloud-native messaging and event streaming, is grounded in the powerful technology of Apache Pulsar. Developers can utilize Astra Streaming to build dynamic streaming applications that take advantage of a multi-cloud, elastically scalable framework. With the sophisticated features offered by Apache Pulsar, this platform provides an all-encompassing solution that integrates streaming, queuing, pub/sub mechanisms, and stream processing capabilities. Astra Streaming is particularly advantageous for users of Astra DB, as it facilitates the effortless creation of real-time data pipelines that connect directly to their Astra DB instances. Furthermore, the platform's adaptable nature allows for deployment across leading public cloud services such as AWS, GCP, and Azure, thus mitigating the risk of vendor lock-in. Ultimately, Astra Streaming empowers developers to fully leverage their data within real-time environments, fostering greater innovation and efficiency in application development. By employing this versatile platform, teams can unlock new opportunities for growth and creativity in their projects.

By leveraging the Azure SignalR Service, you can effortlessly embed real-time communication functionalities into your web application without needing in-depth knowledge of real-time technologies. There is no necessity to configure or oversee servers just to introduce these capabilities into your project. This fully managed service streamlines the integration of real-time communication, alleviating any worries about hosting, scalability, or load balancing, as these elements are handled automatically. You can take full advantage of a wide range of Azure offerings! Seamlessly connect with various services such as Azure Functions, Azure App Service, Azure Active Directory, Azure Storage, Azure Analytics, Power BI, IoT, Cognitive Services, and Machine Learning, among others. By choosing the Premium Tier of SignalR Service, you gain access to advanced enterprise features like auto-scaling, improved service level agreements, support for Azure Availability Zones, and rate limiting. Furthermore, you can effortlessly send detailed metrics to Azure Monitor or integrate with alternative monitoring solutions to effectively oversee your application's performance. This guarantees that your real-time communication capabilities are not only robust and reliable but also scalable to meet increasing demands. Ultimately, the Azure SignalR Service allows developers to focus on their core application functionalities while ensuring efficient communication features are effortlessly integrated.

Eclipse Mosquitto is an open-source message broker licensed under EPL/EDL that is crafted to accommodate multiple versions of the MQTT protocol, including 5.0, 3.1.1, and 3.1. This broker is remarkably lightweight, making it suitable for a diverse array of devices, ranging from low-power single-board computers to high-capacity server systems. The MQTT protocol itself provides an effective mechanism for managing messaging via a publish/subscribe model, which is especially advantageous for Internet of Things applications, allowing for seamless communication with low-energy sensors or mobile devices such as smartphones and embedded systems. Beyond the broker, the Mosquitto project also features a C library that aids in the development of MQTT clients, as well as popular command line tools, mosquitto_pub and mosquitto_sub, which significantly improve user engagement with the MQTT protocol. Furthermore, Mosquitto stands out as a flexible resource for developers seeking to establish messaging frameworks across a wide range of applications, ensuring comprehensive support for various communication needs.

Middleware observability and management software designed for messaging, event processing, and streaming within hybrid cloud environments is known as MESH. - It offers a comprehensive situational awareness® that ensures full observability of Integration MESH. - The platform facilitates secure management of configuration, administration, and deployment processes while also automating these tasks. - Users can track and trace transactions, messages, and data flows effectively. - It enables the collection of data, performance monitoring, and benchmarking. meshIQ empowers users with detailed controls for managing configurations within the MESH, which minimizes downtime and accelerates recovery following outages. The software supports searching, browsing, tracking, and tracing messages to identify bottlenecks, enhance root cause analysis, and increase efficiency. By unlocking the integration black box, it provides visibility across the MESH infrastructure for thorough visualization, analysis, reporting, and predictive capabilities. Additionally, it equips users with the ability to initiate automated actions based on set criteria or intelligent AI/ML-driven decisions, further enhancing operational efficiency and responsiveness. This holistic approach not only improves system reliability but also fosters a proactive stance in managing integration challenges.

CoreDX DDS is an intuitive, cross-platform library designed for Inter-Process Communication (IPC) that supports multiple programming languages. With its remarkable performance characterized by minimal overhead and low latency, it is particularly well-suited for real-time control and capable of handling high message throughput for large-scale data transfers. The library facilitates secure, resilient, and dynamic data exchange, allowing for adaptable communication solutions. Built upon open standards, CoreDX DDS ensures interoperability and long-term sustainability, making it the preferred IPC choice for a wide variety of distributed software applications, such as mobile gaming, consumer electronics, medical devices, advanced Department of Defense systems, and robots operating in space environments. Developers value CoreDX DDS not only for its ease of use but also for its extensive feature set, many of which are difficult to replicate manually and are not available in other IPC libraries. The library includes essential functionalities like built-in end-to-end security, data filtering and storage, data presentation, and event notification options, enabling developers to focus on their core application development without being hindered by complex communication challenges. As a result, CoreDX DDS stands out as a practical and invaluable asset that significantly boosts productivity in software development projects. Furthermore, its adaptability across various domains highlights its versatility and effectiveness in meeting diverse communication needs.