For a long time Firefox Desktop development has supported both Mercurial and Git users. This dual SCM requirement places a significant burden on teams which are already stretched thin in parts. We have made the decision to move Firefox development to Git.

• We will continue to use Bugzilla, moz-phab, Phabricator, and Lando
• Although we'll be hosting the repository on GitHub, our contribution workflow will remain unchanged and we will not be accepting Pull Requests at this time
• We're still working through the planning stages, but we're expecting at least six months before the migration begins