I'm trying to find a simple, straightforward opensource Windows program to compare all files within a directory to all files in a different directory in order to ensure that they are completely identical (basically to verify backups). I'm looking for something more reliable than simply comparing file sizes or dates. I would think the most efficient way to do this would be by using some fast and simple file hash (md5?) to compare the two.
I looked through the "Freeware Replacements for Common Commercial Apps" post, but I didn't see anything like this. Does anyone know of a program like this?