P4Merge is one of the few cross-platform apps that I use on the Mac because the functionality is so good. I hate how the UI looks like a half-assed rip-off of

P4Merge is one of the few cross-platform apps that I use on the Mac because the functionality is so good. I hate how the UI looks like a half-assed rip-off of Windows 95, but it's the only tool I know that shows me everything I want to see when merging / rebasing git branches. I think it also allows comparing 3 or more arbitrary files, which seems like a pretty basic task that most diff tools just can't do at all.