DTD - Document Type Definition File

What is a DTD file

DTD files are plain text files used by developers. These files give further information about different attributes and elements that are used in code documents written in XML, HTML, XHTML or SGML. The purpose of DTD files is to check if a file containing code in one of the aforementioned languages can be parsed correctly.

The information stored in the DTD file specifies elements and attributes used in other code files. Next to these specifications, DTD files can also contain information about the order of elements in, e.g., an XML code, the nesting of the elements and the elements' attributes. DTD files are, most typically, referenced in a web page by specifying it's URL.

Here's a small, but not exhaustive list of programs that can open DTD documents:

  • Altova XMLSpy (Windows, Mac & Linux)
  • Apple TextEdit (Mac)
  • JAPISoft EditiX (Windows)
  • Liquid Technologies Liquid XML Studio (Windows)
  • MacroMates TextMate (Mac)
  • Microsoft Notepad (Windows)
  • Microsoft Visual Studio (Windows)
  • Progress Stylus Studio (Windows)
  • SyncRO Soft oXygen XML Editor (Windows, Mac & Linux)
  • Other Text Editors
Extension DTD
MIME type application/xml-dtd
Useful links