When you click a link to download a file, the MIME type determines what action is taken. If you see an Opening <filename>
dialog asking if you want to save the file or open it with a specified application, that normally means that your Mozilla application cannot handle the MIME type internally, no plugin is installed and enabled that can handle
it and you have not previously selected a download action or helper application to always use for that type of file.
Starting in Firefox 3 and Opera the Opening <filename>
dialog will also appear if you have selected "Always ask" as the action for the file's content type in your (Helper) Applications options/preferences (see below).
The "Open with" option can show a
- Choose or
button, if no application is associated with the file type (shown here on Windows), or it may show a default application for the file type.
You can choose to open the file with that application or you can choose or browse to a different application.
You can use the Browse
button or click the drop-down menu icon and then click on "Other" to open a "Choose Helper Application" dialog, as shown here on Windows.