Лёня... :-)
Но вроде ничего страшного, просто утилита
Lennart has been working on casync the past number of months as a project inspired by rsync and Git while aiming to be a new tool for distributing file-system images. Casync is designed for delivering frequently-updated file-system images over the Internet. He's aiming for casync to be used by IoT, container, VM, portable services, and plain old OS images. Casync could also be used for backups and home directory synchronization.
http://0pointer.net/blog/casync-a-tool-for-distributing-file-system-images.html