Guitone (obviously) uses monotone as its version control system. We're hosting the code on this server, so all you need to do is to grab a monotone binary and create an initial setup:

$ mtn db init -d guitone.mtn
$ mtn -d guitone.mtn pull "guitone.thomaskeller.biz" "net.venge.monotone.guitone"
$ mtn -d guitone.mtn checkout -b "net.venge.monotone.guitone" "guitone"

This will pull and check-out the main branch of guitone into the directory "guitone". There are usually a few other branches (development and release branches); if you want to get these as well, specify:

$ mtn -d guitone.mtn pull "guitone.thomaskeller.biz" "net.venge.monotone.guitone*"