Ranked in these QuestionsQuestion Ranking
Pro Completely free
DiffMerge is free of charge to download and use for both commercial and open source projects. There's no license needed. However, people who want to contribute to the project monetarily can do so.
Pro Folder compare
Pro Cross platform
DiffMerge is cross platform and is available for all major operating systems. This means WIndows, Linux and OSX
Pro Three way merges
DiffMerge supports three way merges.
Con Startup time can be slow
DiffMerge's startup time can be quite slow sometimes.