Meld is great. It's, currently, the best graphical comparison tool open source (and even freeware) has to offer.
To run in on Mac OS X using Mac Ports, you should really follow this small tutorial: Running Meld on OSX 10.7 Lion.
./M6
To run in on Mac OS X using Mac Ports, you should really follow this small tutorial: Running Meld on OSX 10.7 Lion.
./M6