NewsFox

The Statusbar button serves to start NewsFox and to autosubscribe to feeds. The left button opens NewsFox in the current tab, the middle button in a new tab, and the right button presents the autosubscribe menu.
Whether the button is displayed and what information is displayed next to it can be set in the Main options. The text can be hidden until it changes by clicking on it.
When autosubscribe menu items exist on a page, the background of the NewsFox icon turns blue.

The information can be the # of new articles in the current refresh (default), #unread, or nothing.

Browser notes:
Not available in K-Meleon.

about:config

Which button does what is set by newsfox.internal.statusBarButtonOrder with a default of CNM (current tab, new tab, autosubscribe menu) from left to right. You can change it to NxM or whatever you like. Any character not equal to C, N, or M will be ignored, so NxM sets the left button to open in a new tab and the right button to present the menu. Case is ignored: nxm is the same as NXM.

The menu also has options. The menu has items for autosubscribe (A), open NewsFox in current tab (C), open NewsFox in new tab (N), and open a links menu (L). The option for the menu is set in newsfox.internal.statusBarMenuOrder with a default of A. The order is listed from the top of the menu to the bottom so an option of LA would list the link menu above the autosubscribe item(s).

The L (links) menu item presents a menu of all links in the body of the current html page filtered by a regular expression. The regular expression to match is constructed from the string in newsfox.internal.statusBarLinksMatch with a default of 'rss|xml|atom'. So the default links menu (if you display it) presents a list of all body links that contain 'rss' or 'xml' or 'atom' in the href of the link (the search is only over the href). This can be useful for finding feeds that are not present in the of the document. Of course, you can use it to search for links matching whatever you like.