title: Incremental File Copy Tool and NIH
body: <p>For years, one of my most important tools has been incremental copy utility that compares the contents of two directories and shows me which files are newer / older / added / deleted.  Every day I find myself copying folders of source code between my two desktop machines and the server, and such a utility is critical to avoid overwriting newer files with older ones and also to save time by only copying changed files.  In addition, the utility allows me to see new files in the source folder that I don't necessarily want to copy (like temp files) that I instead can delete.</p>
  
  <p>Like anyone who subscribes to the <a href="http://en.wikipedia.org/wiki/Not_Invented_Here" rel="nofollow noreferrer">NIH</a> way of thinking, I wrote my own utility to compare the contents of two folders and let me mark files to be copied, deleted, diffed or ignored.  I've had many versions of this utility going back to DOS, OS/2 and Win32.</p>
  
  <p>I use this utility on a daily basis, and it leaves me wondering: What do others use?  Surely there are similar programs out there to do this...  My utility doesn't have a diff screen, and it would be occasionally nice to see what the difference is between two changed files.</p>
  
  <p>What do you use for comparing and incrementally copying between folders?</p>