Drupal Version Check for Firefox Publisher's description
from White Fir Design LLC
Check what version of Drupal a web page is powered by.
Drupal Version Check is a web browser extensions that checks if pages are powered by Drupal, what version they are running, and indicates if the version in use is outdated. It is available for Firefox and Chrome.
What's New in This Release:Firefox 19.0 and later
System Requirements:No special requirements.
Program Release Status: Minor Update
Program Install Support: Install and Uninstall