Best Free Enterprise Service Bus (ESB) Software of 2025

A powerful iPaaS platform for integration and business process automation. Linx is a powerful integration platform (iPaaS) that enables organizations to connect all their data sources, systems, and applications. The platform is known for its programming-like flexibility and the resulting ability to handle complex integrations at scale. It is a popular choice for growing businesses looking to embrace a unified integration strategy.

DreamFactory is a REST API Management Platform. Auto Generate REST APIs. A cloud-based or on-premise API generation platform that is enterprise-grade. Instantly generate database APIs to build faster applications. The biggest bottleneck in modern IT is eliminated. Your project can be launched in weeks instead of months. DreamFactory creates a secure, standardized and reusable, fully documented, live REST API. DreamFactory can integrate any SQL or NoSQL file storage system or SOAP service. It instantly creates a RESTAPI with Swagger documentation, user role, and more. Every API endpoint is secured with User Management, Role Based Access Controls, SSO Authentication and Swagger documentation. Rapidly create mobile, web and IoT apps using REST-based APIs. DreamFactory offers example apps for iOS, Android and Titanium.

Service-oriented architecture is now a reality. Warewolf allows developers the ability to create and manage microservices in a visual, flow-based, drag-and-drop environment. It's a revolution in the way we think about SOA and how we use it. Warewolf doesn't require that you learn anything new. Warewolf will be easy to use if you have used a drag-and-drop design tool. Complex integrations and systems can now be created as easily as a flowchart. Warewolf Studio allows you to design and layout your microservices exactly as you would normally. Next, enter the credentials and variables, and add connectors as needed. Finally, you can call Warewolf directly from your application.

InterSystems Ensemble provides a data platform that allows you to create integrated solutions, orchestrate and use messaging queues. Built-in Data Repository and Message Repository Ensemble, according to the vendor, offers high-performance data processing and guaranteed message delivery. It also allows for resumption and resumption business processes that have been interrupted. It also provides analytics of both historical and real-time data and reliability through its database mirroring technology. Framework and adapter library Ensemble adapters allow for out-of-the box connectivity and data transformations for packaged apps, databases, industry standard protocols, protocols, and technologies - such as SQL, HL7 and SOAP. SOAP and object inheritance make it easier to create any custom adapters. Ensemble's unit-testing service allows custom adapters to be tested without the need to complete the entire project.

NServiceBus is the most user-friendly service bus for.NET. NServiceBus is used by more than 50,000 developers every day. NServiceBus is backed by a solid distributed development methodology and a global community of experts, consultants, and contributors. It offers enterprise-grade scalability for your workflows. NServiceBus is used extensively in mission-critical systems, business domains, and usage scenarios. NServiceBus' performance and scalability are proven and ready to take on the most difficult assignments. Reliable integration with automatic restarts. Reliable by default. With configurable mechanisms to retry failures using best practices in messaging and lessons learned from thousands production usage scenarios. Workflow and background task scheduling.

MetaMate is a semantic service bus open source that provides a unified interface for accessing diverse sources of data, including APIs and blockchains. It also supports websites, peer-to-peer networks, and other web services. MetaMate allows seamless interaction with different services by mapping vendor-specific data to an abstract schema graph. The community-driven approach of MetaMate allows contributors to create new types and fields. This ensures that the system is updated with real-world data. The platform's type-system is derived from widely used data transmission technologies, such as GraphQL and gRPC. It also incorporates Thrift and OpenAPI to facilitate compatibility with different protocols. MetaMate enforces the backward compatibility of services and applications that are built on its platform programmatically. Using its command-line, it can also generate SDKs that are tailored to the specific needs of a project, and only cover the subsets of the schema graph that are desired.