For one Windows application I want to implement text files comparison which can produce unified diff. Such diff can be further used in other utilities like Apply patch in TortoiseSVN. Is there any good FPC or Delphi implementation of that. I didn't found simple answer after short googling. Algorithm for GNU diff utility is somehow described so implementation from scratch can be possible. But if somebody already has such unit/library/component/package then it would make more sense to use existing solution.