Ubuntu's rsync is samba rsync. It's not part of the samba project per se, but it is made by the same guy and the official url is https://rsync.samba.org/ https:

Ubuntu's rsync is samba rsync. It's not part of the samba project per se, but it is made by the same guy and the official url is https://rsync.samba.org/ https://rsync.samba.org/ so it's entirely fair to call it samba rsync in my opinion.