Warning: This page was last updated in 1994, so many of the links are broken.

Document Types

Web browsers use external programs called viewers or heplers to display/play certain multimedia formats that they cannot display themselves. They do this by mapping file name extensions (e.g., .txt in MYFILE.TXT) to Multipurpose Internet Mail Extensions (MIME) types/sub-types (e.g., text/plain). MIME types are then mapped into viewers or helpers programs that you have loaded on your system.

The following also have information on file types:

file name extension list at NCSA.
A more complete list of file name extensions (many without MIME types) are in the File Name Extensions list here.
MIME-types: A list of default mime types in standard software packages.
Extension to MIME type lists are at NCSA
Extension to MIME list at bsdi.
list of file formats at NASA
List at Yahoo
Microsoft MIME types
standard document formats at the ITU. (local copy)
Multimedia File Formats on the Internet
File Name Extension list from Allison Zhang
Common Internet File Formats at Internet Literacy
Cross-platform file formats at mps.org and mcad.edu

RFC 1521 (replaces 1341) - MIME (Multipurpose Internet Mail Extensions) says in Appendix E

  "In order to ensure that the set of such values is
   developed in an orderly, well-specified, and public manner, MIME
   defines a registration process which uses the Internet Assigned
   Numbers Authority (IANA) as a central registry for such values."
  See Media-types at IANA.  Send mail to iana@ISI.EDU for additions.

These are now referred to as Media-Types on their server.

See also the discussion of file name extensions list

Examples of the common MIME types are in the Mime Page here.

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10/5/94.