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This message is intended for anyone who is responsible for the management and/or maintenance of web-server software. I kindly request about 5 minutes of your time for the following important issue.

The popular PNG image-format has been around for many years. Another, but lesser known, relative of PNG is MNG. MNG stands for Multiple-image Network Graphics and is pronounced "ming". This new animation format is intended as a full replacement and major (patent free!) enhancement over animated GIFtm.

A sub-format of the MNG specification is JNG (JPEG Network Graphics; pronounced "jing"), which adds transparency to highly-compressed (photographic) images in relation with the JPEG format. For more information on these image-formats, I would like to recommend the MNG homepage, maintained by Greg Roelofs, who also maintains the PNG homepage.

The problem I need to address is that these new image-formats are not supported by standard web-server software. It is however very easy to fix this. It will only take a little of your time to make corrections to the setup of your web-server(s), and it will be greatly appreciated by your customers.

The correction required is to simply add the proper file-extension and mime-type pairs in your web-server software (the PNG parameters are given as reference).

Image type



Magic-string / signature













This will ensure that the web-server software will send the appropriate identification to client-software which will then process the images as intended. The changes have already been reported to the Apache group. You can see the feature request here. It explains the required changes for Apache server-software.

Allthough future versions of web-server software may be expected to implement this as a standard feature, all users of MNG and JNG would appreciate this intermediate fix until the software developers have implemented and distributed the feature. This ensures we can all start enjoying this highly addictive image-/animation-format as soon as possible...

Thank you very much for your cooperation!

With kind regards,

Gerard Juyn.