OPML Support is an extension for the Mozilla Firefox Web browser that adds OPML import/export functionality to the Firefox Bookmarks manager. OPML is a file type that is widely used to distribute lists of RSS/newsfeeds.
When exporting, you can choose to export your livemarks (feeds), bookmarks, or both. When importing a file, you can choose to import only the livemarks, only the bookmarks, or all of the links listed in the file. You can also choose whether to import/export links in their folder hierarchy.
Note: watch the OPML Support section of my blog for information on updates to this extension.