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), Araxis Merge (Paid) and FileMerge (Free).
Beyond Compare allows you to compare files and folders. By using simple, powerful commands you can focus on the differences you're interested in and ignore those you're not. You can then merge the changes, synchronize your files, and generate reports for your records.
Merge is the visual file comparison (diff), merging and folder synchronization application from Araxis. Use it to compare and merge source code, web pages, XML and other text files with native application performance.
Meld is a visual diff and merge tool targeted at developers. Meld helps you compare files, directories, and version controlled projects. It provides two- and three-way comparison of both files and directories, and has support for many popular version control systems.