Hmm, good question. I know of one such implementation, which is Delta RPM, which works the way I described it.
But I’m not sure, if they just designed it to fit into the current architecture, where all their mirrors and such were set up to deal with package files.
I could imagine that doing it rsync-style would be really terrible for server load, since you can’t really cache things at that point…





Since no one mentioned it yet, this is the classic card game “Klondike”.
KPatience is a program that implements multiple such card games…