What is MIME type "application/vnd.cinderella"?

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

application/vnd.cinderella is a MIME type for files used by the Cinderella software.
It stores dynamic geometry data and interactive math models. The file, with extension CDY, holds instructions that the program uses to display and manipulate geometric constructions.
This format lets users create, modify, and animate mathematical diagrams.

Dynamic Constructions: Save interactive settings for geometric figures.
Math Modeling: Store equations and commands for simulations.
Visual Diagrams: Record and reproduce precise constructions for presentations and teaching.

For more details on the file extension, check the reference at this resource.

Associated file extensions

.cdy

Usage Examples

HTTP Header

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


    Content-Type: application/vnd.cinderella

HTML

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


    <a href="file.dat" type="application/vnd.cinderella">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/vnd.cinderella');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.cdy

FAQs

What is the application/vnd.cinderella MIME type used for?

This MIME type is specifically used to identify files created by Cinderella, a dynamic geometry software. It tells web servers and clients that the data being transferred is a geometric construction or math simulation, typically associated with the .cdy file extension.

How do I configure Apache to serve .cdy files correctly?

To ensure Apache serves Cinderella files with the correct headers, add the following line to your .htaccess file or httpd.conf: AddType application/vnd.cinderella .cdy. This prevents the browser from misinterpreting the file as plain text.

Can web browsers open application/vnd.cinderella files natively?

No, standard browsers like Chrome or Firefox cannot render these files directly. When a browser encounters this MIME type, it will typically download the file or attempt to launch the installed Cinderella desktop application. For direct web embedding, developers often export constructions to HTML5 using CindyJS.

How do I add this MIME type to an Nginx server?

You can enable support in Nginx by editing the mime.types file or your server block configuration. Add the following entry within the types block: application/vnd.cinderella cdy;. Afterward, restart or reload Nginx to apply the changes.

Why is my Cinderella file downloading as a generic binary file?

If the server is not configured with application/vnd.cinderella, it may default to application/octet-stream. This generic MIME type tells the browser the file is arbitrary binary data, forcing a download instead of handing it off to the associated geometry software.

What is the relationship between this MIME type and Java?

Historically, Cinderella files were often displayed on the web using Java Applets, which relied on this MIME type to load the correct Java archive. While Applets are deprecated in modern browsers, the application/vnd.cinderella type remains the standard for identifying the raw source files on a server.

General 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.