GNU Emacs is finally in the process of transitioning to Git for their revision control system rather than GNU Bazaar.
Eric S Raymond has been leading the call for getting GNU projects still reliant on Bazaar to switch over to Git. To Emacs developers back in January, Raymond
wrote, "The bzr version control system is dying; by most measures it is already moribund. The dev list has flatlined, most of Canonical's in-house projects have abandoned bzr for git...In practice, I judge that sticking with bzr would have social and signaling effects damaging to Emacs's prospects. Sticking to a moribund version-control system will compound and exacerbate the project's difficulty in attracting new talent. The uncomfortable truth is that many younger hackers already think Emacs is a dinosaur - difficult, bulky, armor-plated, and generally stuck in the last century. If we're going to fight off that image, we cannot afford to make or adhere to choices that further cast the project as crusty, insular, and backward-looking."
Nearly one year after leading GNU Emacs developers to abandon Bzr for Git, that transition is finally taking place. Eric S Raymond
began yesterday migrating over Emacs to Git -- including its very lengthy history and thus is a big process to migrate over to using Git. Besides encouraging open-source developers to leave Bazaar in favor of Git, ESR has also been active in encouraging projects to finally abandon CVS as well.
Bleeding edge Emacs users wishing to make the switch over to Git or somehow aren't yet familiar with the Git processes, see
this Emacs Wiki page.