SyncToy

Download: SyncToy
Purpose: File synchronization
Platforms: Windows 7, Vista, XP; Windows Server 2008, 2003; 64-bit version available
Cost: Free

Microsoft's free SyncToy originally appeared as part of the Windows XP PowerToy package. While most of the old XP PowerToys passed on to the big bit bucket in the sky, SyncToy has been improved regularly. The latest version takes advantage of Ray Ozzie's Sync Framework. SyncToy 2.1 has been around for almost a year, and it works amazingly well.


To use SyncToy, pick two folders. Let's call one "Left" (for reasons manifest in the screenshot below) and the other "Right." Here's what you can do:


Synchronize: New files, along with files that have changed since the last Synchronize, are copied between the Left and Right folders. If a file has been renamed or deleted in one, it's renamed or deleted in the other.
Echo: New and changed files are copied left to right, with renamed and deleted files on the left renamed or deleted on the right.
Contribute: Same as Echo, but deletions on the left are not deleted on the right.