QUOTE
How do I get my browsers to use the Flip4Mac?
That is sometimes the hardest part.
In FF ( later versions, anyway ), open Prefs. Look for "Content" as a tab or icon. Hopefully, near the bottom of the window will be a "File Types" area with a button labeled "Configure" or "Manage". Clicking that button will show you a list of file types that it already knows how to handle. You can edit what FF uses for each file type; you'll be asked how to handle it, usually with a normal nav window where you select an app to handle that file.
Of course, you can also remove that type from the list. If you do that, the next time the browser sees that kind of file, it
should ask you what to do with it; save to disk, ignore, call the National Guard or just ignore it. You will now have another opportunity to assign an app/plugin to handle the file.
Not really sure how other browsers do this task but I would think in similar ways but perhaps with different terms.