are you talking about pdiff for list files, or debdelta (http://debdelta.debian.net/html/index.html http://debdelta.debian.net/html/index.html)? I've never see

are you talking about pdiff for list files, or debdelta (http://debdelta.debian.net/html/index.html http://debdelta.debian.net/html/index.html)? I've never seen debdelta used in the wild, but I know Fedora's delta RPMs work quite well.