Binary package “kdiff3” in ubuntu mantic

compares and merges 2 or 3 files or directories

 KDiff3 compares two or three input files and shows the differences
 line by line and character by character. It provides an automatic
 merge facility and an integrated editor for comfortable solving of
 merge conflicts. KDiff3 allows recursive directory comparison and
 merging as well. KDiff3 also has KIO support, so it can access to
 remote files and compressed archives.