[qaexl]

Meld is the only tool I know of that shows a 3-panel merge. That's the killer feature for me.

Now, if there were an OSX-native app that does 3-panel merges, I'd gladly switch off of Meld.

[j_s]

I believe the cross-platform (so semi-native) PlasticSCM's included xmerge has what you're looking for:

http://codicesoftware.blogspot.com/2010/07/xmerge-to-merge-r...

[qaexl]

Xmerge looks great. Too bad I'm on git.

[psantosl]

You can always switch to Plastic!! Now it is FREE, didn't you know. Or, as last resort: why don't you use Xmerge with Git?? :)

[naish]

Araxis Merge might be what you are looking for (Professional version only).

http://www.araxis.com/merge/

Unfortunately, it is not inexpensive.

[turtle4]

Diffmerge from sourcegear is free and runs natively on os x (in addition to win and Linux) and does 3 panel merges, as well as folder diffs pretty well.

[kbd]

kdiff3 works on mac