Helper Applications

Usually, the server tells Mosaic the MIME type of the file it is sending. Originally, MIME--Multipurpose Internet Mail Extensions--was just a method of including images, sounds and other non-text information in a mail message. MIME has now been incorporated into other systems such as the World Wide Web. See "MIME" on page C-1 for more information.

Based on a file's MIME type, Mosaic knows whether to handle the file itself (i.e., if it is an HTML file) or to pass it off to an external viewer.

Some servers--such as FTP servers--do not use MIME types. In that case, Mosaic tries to infer the MIME type from the file extension. For example, a file ending in .gif is assumed to be a GIF file; one that ends in .html is assumed to be an HTML file.

You are able to modify the MIME types in the following ways:

• change which external viewer is used for a given MIME type
• define a new MIME type for a new file type
• add a new file extension and specify which MIME type it corresponds to