What is MIME type "application/x-msdos-program"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

The MIME type application/x-msdos-program signals that a file is a DOS executable. It embeds an MZ header that tells the operating system how to run the code.

Files marked with this type include the traditional DOS-style programs like EXE and dynamic libraries like DLL.

Main use case: Running legacy DOS programs via emulation or compatibility modes.
Legacy support: Assists systems in identifying and processing traditional executable formats.
Technical identification: Uses a DOS MZ header to start file execution reliably.
Development and analysis: Helps tools and developers recognize and work with old binary formats.

This MIME type is less common on modern systems but remains important for accessing and preserving historic software. For more details on how MIME types work, visit MIME on Wikipedia.

Associated file extensions

.exe, .dll

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/x-msdos-program

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/x-msdos-program">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');
    
    http.createServer((req, res) => {
      res.setHeader('Content-Type', 'application/x-msdos-program');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.exe, .dll

FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.