KDiff3 is a file and folder diff and merge tool which
- compares and merges two or three text input files or folders,
- shows the differences line by line and character by character(!),
- provides an automatic merge-facility,
- has an editor for comfortable solving of merge-conflicts,
- provides network transparency via KIO,
- has options to highlight or hide changes in white-space or comments,
- supports Unicode, UTF-8 and other file encodings,
- prints differences,
- supports version control keyword and history merging.