Zsync, a evolution of rsync

Colin Phipps has updated rsync to create zsync, an rsync based replication system where the rsync algorithm runs on the client side. 

Executing the rsync algorithm on the client side has two main advantages: first of all, you can zsync over any protocol (zsync is able to syncronize over HTTP). Additionally, it avoids the high server load associated with running the algorithm on the server.

Ah! And it is able to handle compressed files.