Statusbar with HTTP response header monitor.
This is Firefox extension for display on statusbar panel any HTTP response header of top level document returned by a web server. Example: Server (by default), Content-Encoding, Content-Type, X-Powered-By and others.
Important: This extension obtains headers from LiveHTTPHeaders. Therefore, in order to use HeaderMonitor first install extension LiveHTTPHeaders from http://livehttpheaders.mozdev.org/installation.html