Which language is primarily used for defining flows in MuleSoft?

The primary language used for defining flows in MuleSoft is XML (Extensible Markup Language). In Mule applications, the configuration of various components, such as processors, connectors, and other flow properties, is predominantly done through XML files. This structured and hierarchical format allows for clear representation of the application's architecture and integrations.

XML is specifically chosen because it enables rapid development and easy readability of configurations, facilitating better management of complex integrations. By leveraging XML, developers can make use of schemas that ensure the correctness of the configuration. This is crucial in a development environment where integrations often involve various external systems and data formats.

Other languages mentioned, such as JavaScript, JSON, and HTML, serve different purposes. JavaScript can be used for data transformation within flows but is not the language for flow definition. JSON is commonly used for data interchange but not for defining flow configurations. HTML is primarily a markup language for structuring content on the web and is not applicable in the context of defining MuleSoft flows.