A bit of quilt

Hi, As I know quilt is used by maintainers. But kernel source code is maintained in git repo. So I want to know how git and quilt work together. In mutt I have seen that a mail sent by Mr. GregKH has quilt mail as user agent and git-send-email as x-mailer. It means he is using git-send-email as a backend for quilt mail. Last but not least, I think if a developer starts using quilt to maintain his diferent versions of a patch, it will ease a maintainer job. Regards, Amit Kumar