KDiff3 (64-Bit) is a graphical text difference analyzer for up to 3 input files, provides character-by-character analysis and a text merge tool with integrated editor.
License: Open Source
WinMerge is a Windows-only comparison tool known for its ease of use and powerful file and directory comparison features, but it lacks three-way merging capabilities. On the other hand, kdiff3 supports three-way merging and is cross-platform, making it a better choice for users needing advanced merging features and customization.