This program has been invaluable when backing up folders to verify that a true clone exists. Verifying a copy of such libraries as iPhoto, iTunes or Fonts was very tedious before I had zsCompare as a tool. If one chooses an entire hard drive, it will cause the program to crash. I just did a comparison on a 30gig iPhoto folder without difficulty. I have had no problem with it crashing on a G4 running Tiger. There is good customer support from the developers via email and suggest anyone having difficulty email them.

One scenario which used to drive me nuts was copying a folder with multiple subfolders to another location. During the copying process, I'd get a message saying some file could not be read. When I'd look at the destination folder, I'd have to manually go through each folder and included subfolders to see which files were copied and which ones aborted. Now I simply load up zsCompare, immediately I have side by side windows listing the origin folder and destination folder, I can confirm which files exist in each location and I can easily select those which I want to copy to the other location. I press send.

There is a version for Windows as well as Mac. I have used it on a PC running XP Pro. I have not tried zsCompare in Leopard yet on a MacBook Pro.