Registration of media type model/x3d+XXX

[Leonard Daly]

Per the instructions in IETF RFC 4288, the Web3D Consortium 
(http://web3d.org/) is submitting model/x3d+XXX as a new MIME type. 
Please contact me if there are clarifications or questions.

Thank you,

Leonard Daly
X3D WG Co-Chair, Web3D Consortium


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Type name: model

Subtype names:
x3d+vrml
x3d+xml
x3d+binary

Required parameters:
None

Optional parameters:
None

Encoding considerations:
This application represents the different MIME types used for three 
different encodings of the X3D ISO standard (see [1]). The standard 
defines an abstract information structural representation, for which 
several file formats are available. These formats are currently defined 
to be:

VRML-Classic: (old-style curly brace format of the VRML97 ISO standard). 
UTF-8 (8-bit text) is to be supported. The recently introduced UTF-8 BOM 
cannot be supported by definition of the specification.

XML: Encoding requirements as per the XML standards.

Binary: (Effectively a binary XML encoding scheme based on the outcome 
of the W3C binary XML working group process). Still a work in progress 
and standardisation is not yet complete.

Each content type may have an addition Content-Encoding to indicate 
whether the content has been compressed using GZIP in addition to the 
basic textual encoding. This is also indicated by modifying each file 
extension with the character "z". For example, the plaintext 
VRML-encoded file format would use the extension ".x3dv", and if 
compressed using GZIP uses the extension ".x3dvz"

Security considerations:
Scripting is defined as being available for the specification. Two 
languages are defined: Java and ECMAScript. Each scripting language is 
controlled by its local security model. As the content may run in many 
different situations, the X3D specification does not impose specific 
security policies. For example, some standalone applications will want 
to directly interact with the local file system, network or database, 
while others that run in a web browser would use the web-browser's 
security model.


Interoperability considerations:
The definition of the file format is maintained by the Web3d Consortium 
(http://www.web3d.org) and published through the ISO process. Several 
revisions of the specification have been made and it continues to be 
made. All revisions use the same MIME type definitions, and are 
backwards compatible internally and structurally. In addition, each of 
the file format encodings may be losslessly transformed between each other.

Published specification:
All revisions of the X3D specification can be found here:
http://www.web3d.org/x3d/specifications/

Several revisions of each specification exist. The abstract 
specification is ISO/IEC 19775:2004. The individual file formats, which 
also specify the matching MIME types, are parts of the ISO/IEC 19777 
specification.

Applications that use this media type:
There are well over 20 - both browsers, exporters and importers.

Additional information:

Magic number(s):
x3d+vrml: “#X3D”
x3d+xml: Use XML’s specification
x3d+binary: “#X3D”

File extension(s):
x3d+vrml: .x3dv, .x3dvz
x3d+xml: .x3d, .x3dz
x3d+binary: .x3db

Macintosh file type code(s):

Person & email address to contact for further information:
Leonard <mailto:Leonard> Daly (X3D Working Group Co-Chair) 
Leonard.Daly at realism.com
Alan Hudson (Web3d Consortium President) giles at yumetech.com 
<mailto:giles at yumetech.com>

Intended usage:
COMMON

Restrictions on usage:
None

Author:
The Web3D Consortium

Change controller:
The Web3D Consortium

The X3D standard is a continuation of the VRML standard that is defined 
in RFC2077. As part of this work, several large modifications were made 
to the file format and specification. The basic premise for the 
specification continues the VRML philosophy. The MIME types and file 
extensions were changed to indicate this modified standard.


-- 
+--------
| Leonard Daly
| Internet Solutions, eBusiness Specialist http://realism.com/
| LA ACM SIGGRAPH, Electronic Services Chair
| X3D Book: http://x3dGraphics.com
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