KDiff3 is a diff and merge program that
- compares or merges two or three text input files or directories,
- shows the differences line by line and character by character (!),
- provides an automatic merge-facility and
- an integrated editor for comfortable solving of merge-conflicts,
- supports Unicode, UTF-8 and other codecs, autodetection via byte-order-mark "BOM"
- supports KIO on KDE (allows accessing ftp, sftp, fish, smb etc.),
- Printing of differences,
- Manual alignment of lines,
- Automatic merging of version control history ($Log$),
- and has an intuitive graphical user interface