There are many alternatives to DiffMerge for Mac and since it's discontinued a lot of people are looking for a replacement. The best Mac alternative is Meld, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to DiffMerge and many of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to DiffMerge are Beyond Compare (Paid), Kaleidoscope (Paid), FileMerge (Free) and Araxis Merge (Paid).
Guiffy is a diff merge tool and folder compare application and API. SureMerge is the most trustworthy source code 3-way merge tool available. Advanced features include tuneable inline diff highlighting, syntax highlighting and a blend of 3 diff algorithms.
Text Compare lets you instantly see the difference between two pieces of text. Compare text by paragraph, word or character. Paste in two pieces of text, and Text Compare will highlight what has been inserted in, or deleted from, the original text.