All Azure services, including the Azure Management Portal, provide their own REST APIs for their functionality. They can, therefore, be accessed by any application that RESTful services can process.

In order for software developers to write applications in the programming language of their choice, Microsoft offers wrapper classes for the REST APIs.

These are available as an Azure SDK for numerous programming languages (for example, .NET, Java, and Node.js) here at https://github.com/Azure.