SSHFS allows you to mount a remote filesystem using SFTP. Most SSH servers support and enable this SFTP access by default, so SSHFS is very simple to use - there's nothing to do on the server-side.
$ sudo apt-get install sshfs
$ sshfs user@server-ip:/server-workdir/ /local-workdir/mount-point/
Rsync command-line tool.
$ sudo apt-get install rsync grsync
$ rsync -azv user@server-ip:server-to-be-copied-dir/ /local-copied-dir/
$ rsync -azv /local-to-be-copied-dir/ user@server-ip:server-copied-dir/
$ sudo apt-get install git-cola
$ cola