Microsoft Interface Definition Language

Microsoft Interface Definition Language (MIDL) is a language used to define interfaces between client and server programs in distributed computing environments. MIDL enables developers to create standardized interface definitions that facilitate communication between different software components, whether they are running on the same machine or across a network.

Definition

The MIDL compiler is included with the Microsoft Platform Software Development Kit (SDK) and allows developers to create Interface Definition Language (IDL) files and Application Configuration Files (ACF) required for:

• Remote Procedure Call (RPC) interfaces for distributed computing

• COM/DCOM interfaces for component-based programming

• Type libraries for OLE Automation support

MIDL acts as a bridge between different programming languages and platforms by generating language-specific stub code that handles the low-level details of inter-process communication.

Architecture and Components

Application

MIDL can be used in various client/server applications:

• Windows-based applications − All client/server applications on Windows operating systems

• Heterogeneous networks − Cross-platform environments including Unix and Apple systems

• Distributed systems − Applications requiring communication across network boundaries

Microsoft supports The Open Group DCE standard for RPC interoperability, ensuring compatibility with industry-standard distributed computing frameworks.

Developer Requirements

Different levels of expertise are required depending on the MIDL usage scenario:

Runtime Environment

Windows operating systems include the necessary run-time libraries for applications that use MIDL-generated interfaces. The MIDL compiler and all components of the RPC development environment are automatically installed when the Windows SDK is installed on a development machine.

The runtime environment provides essential services including marshaling and unmarshaling of data between different address spaces, automatic memory management, and error handling for distributed operations.

Conclusion

MIDL is a crucial tool for developing distributed applications on Windows platforms, providing standardized interface definitions for RPC and COM communications. It simplifies cross-platform development by generating the necessary stub code and type libraries, enabling seamless integration between client and server components across heterogeneous network environments.