Changes

Every day, Mozilla developers write code that is merged into a common code repository (mozilla-central) and every day that code is compiled so as to create a pre-release version of Firefox based on this code for testing purposes, this is what we call a Nightly build. Once this code matures, it is merged into stabilization repositories (Beta and Dev Edition) where that code will be polished until we reach a level of quality that allows us to ship a new final version of Firefox to hundreds of millions of people. This development process used to ship a new version of Firefox every 4 to 5 to 8 weeks is called the Train Model.  {| style="border: 1px solid darkgray; width: 50em"|+ style="font-weight: bold;" |Firefox channels until April 18, 2017|- style="color: black; background-color: white;"! | 55! | 54! | 53! | 52! | 51|- style="color:white;"| style="background-color: black;text-align: center" | Nightly| style="background-color: darkblue;text-align: center" | Aurora| style="background-color: orange;text-align: center" | Beta| style="background-color: green;text-align: center" | Release| style="background-color: transparent" | | style="background-color: transparent" | |- style="color:white;"| style="background-color: transparent;text-align: center" | | style="background-color: black;text-align: center" | Nightly| style="background-color: darkblue;text-align: center" | Aurora| style="background-color: orange;text-align: center" | Beta| style="background-color: green;text-align: center" | Release| style="background-color: transparent" | |} After April 18, 2017, [http://release.mozilla.org/firefox/release/2017/04/17/Dawn-Project-FAQ.html the Aurora channel ceases to exist] and the train model takes this form:

! | 5574! | 5473! | 5372! | 5271