Starting with Firefox 5, the Gecko (rendering engine) version numbering will now be the same as Firefox version. Presently with Firefox 4, the Gecko version is 2.0 (though it was 1.9.3 during the Alpha releases as Firefox 3.7). Now with Firefox 5, Gecko version will also be 5. I first noticed this when I was looking at the build id information for the Firefox 6 Nightly build I am currently using. Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:6.0a1) Gecko/20110415 Firefox/6.0a1 ID:20110415030205 The rv:6.0a1 portion refers to the Gecko version, which in this case is 6.0 Alpha 1. Compare this to…

Just Released Firefox 5 Aurora – April 14th Schedule this Coming Week None Future Release Firefox 3.5.19 – April 26th Firefox 3.6.17 – April 26th Firefox 4 Macaw (4.0.1) – April 26th Firefox 5 Beta – May 17th Firefox 6 Aurora – May 24th Firefox 5 Release – June 21st