Track changes in files

All,

Is there any command or method by which we can track changes in a file in Unix (Something similar to track changes in a word document).

I know there is CVS which is used to store code changes and track changes in the code. But other than CVS any way to find out changes done in a file which is not stored in CVS.

Regards,
Rahul Rathod.

A very nice and easy to implement program is RCS.