changetrack is a program to monitor changes to files. If files are modified one day, and the machine starts working incorrectly some days later, changetrack can provide information on which files were modified, and help locate the problem. Changetrack will also allow recovery of the files from any stage.
The Revision Control System (RCS) manages multiple revisions of files. RCS automates the storing, retrieval, logging, identification, and merging of revisions. RCS is useful for text that is revised frequently, for example programs, documentation, graphics, papers, and form letters.