Glossary · Automation software engineering and architecture
Middleware
German: Middleware
In software engineering, middleware is software that sits between the operating system or network and applications and provides common services such as communication, messaging, data access or security, so applications need not implement them.
- Software engineering
In one sentence
Middleware sits between operating system or network and applications, providing shared services such as messaging, data access and security.
Example
An OPC UA SDK and an MQTT broker act as middleware between the machine controllers and the plant's data applications.
How it applies
- Engineering: Middleware hides network and platform details behind an API, which speeds up integration and makes applications portable. It also becomes a critical dependency whose versions and configuration must be managed.
- Security: Middleware often handles authentication and encryption; its configuration is part of the plant's security design under IEC 62443.
- Documentation: State which middleware and versions the product requires or ships, which ports and services it opens, and who is responsible for updating it. This information feeds the installation guide and the security documentation.
Middleware vs. operating system
The operating system manages hardware resources for one device. Middleware builds on it and provides services that span applications or devices, such as messaging between machines.