xxdiff binary package in Ubuntu Xenial amd64

 xxdiff is a powerful tool for viewing the differences between two or three
 files, or two directories, and can be used to produce a merged version. The
 texts of the two or three files are presented side by side with their
 differences highlighted with colors for easy identification. Among its
 features are:
 .
  * Compares two or three files, or two directories (shallow and recursive)
  * Horizontal highlighting of diffs
  * Interactive merges, previewing and saving of the resulting output
  * Unmerges CVS conflicts and displays two files, to help resolve conflicts
  * Fully customizable with a resource file
  * Features and output that ease integration with scripts
 .
 The scripts that accompany xxdiff can be found in the xxdiff-scripts package.

Source package