The metrics in this gist come from Mercurial. They are produced with the help of the mozext extension, which can be obtained at https://hg.mozilla.org/hgcustom/version-control-tools/file/default/hgext/mozext.
See http://gregoryszorc.com/blog/2013/11/08/using-mercurial-to-query-mozilla-metadata/ for usage info.
$ hg log -r 'tree(central) and not merge() and firstpushdate("2013")' --template '{author}n' | sort | uniq -c | sort -n