KDiff3 is a program that compares or merges two or three text input files or directories, showing the differences line by line and character by character. KDiff3 provides an automatic merge-facility and an integrated editor for comfortable solving of merge-conflicts. The program also supports KIO on KDE (allows accessing ftp, sftp, fish, smb etc.), and has an intuitive graphical user interface. More information and downloads are available from the KDiff3 Web Site.

Kompare is a KDE frontend to the Open Source diff application. Kompare is shipped as part of the KDE SDK. More information is available from the KDE Web Site.

xxdiff is a graphical file and directories comparator and merge tool. xxdiff is useful for comparing two files, three files, or two directories (shallow and recursive). It provides horizontal diffs highlighting and files can be merged interactively with visualization and saving of the resulting output. xxdiff has features to assist in performing merge reviews/policing and can unmerge CVS conflicts in automatically merged file and display them as two files, to help resolve conflicts. xxdiff uses external diff programs to compute differences: works with GNU diff, SGI diff and ClearCase's cleardiff, and any other similar diff tools. More information and downloads can be found at the xxdiff Web Site.

TkDiff is a graphical front end to the diff program. It provides a side-by-side view of the differences between two files, along with several innovative features such as diff bookmarks and a graphical map of differences for quick navigation. More information and download can be found on the TkDiff Web Site.

GTKdiff is a graphical diff tool. It has diff3 and merge features. It's written with GTK+. After gtkdiff-0.8.0, it requires GNOME. More information and download can be found the GTKdiff Web Site.

Meld is a visual diff and merge tool. It integrates especially well with CVS. The diff viewer lets you edit files in place (diffs update dynamically), and a middle column shows detailed changes and allows merges. The margins show location of changes for easy navigation, and it also features a tabbed interface that allows you to open many diffs at once. More information and download can be found the Meld Web Site.

ExamDiff Pro is a powerful yet intuitive and easy to use visual file and directory comparison tool for Windows. It features unique functionality that distinguishes ExamDiff Pro from other comparison programs. If you used WinDiff or UNIX diff before, you will find that ExamDiff Pro offers much more efficient and user-friendly way to compare files and folders. More information and download can be found the PrestoSoft the developers of ExamDiff.