KDiff3

KDiff3 is a graphical utility that lets users compare the contents of two or three files side‑by‑side, highlighting differences at the line and character level. It also supports directory comparison, showing which files have been added, removed, or altered between two folder trees. When discrepancies are found, the program provides an interactive merge view where users can select which changes to keep, edit conflicts manually, and save the resulting merged file.

The tool is aimed at developers, system administrators, and anyone who needs to reconcile divergent versions of source code, configuration files, or documentation. It runs on macOS and is distributed under the GNU General Public License v2.0 or later, allowing free use and modification.

KDiff3’s distinctive features include three‑way comparison, visual diff highlighting, and an integrated merge editor that works with both individual files and entire directories, offering a stable and mature solution for routine file‑version management.