1)   ViceVersa PRO 2.0
Windows File Synchronization, File Replication and Backup Software. ViceVersa PRO delivers an easy way to backup, mirror, replicate and synchronize files and folders. ViceVersa works with any type of storage media on laptop, desktop, servers.
File Synchronization, File Replication, File Backup, Backup Software, File Mirroring, File Distribution, Folder Synchronization, Synchronize Files, Synchronize Folders,

 2)   AJC Directory Synchronizer 2.4.9
AJC Directory Synchronizer makes it easy to synchronize files and compare folders between any two locations. Synchronize large numbers of files between computers, sync laptop to desktop, mirror to backup drive, sync mp3 player etc.
directory, folder, file, compare, synchronise, synchronize, diff, compare folders, compare directories, compare files,

 3)   Comparator Fast 1.0.0.19
Simplifies the comparison / verification / synchronization status of two different directories on any media (local drives, network drives, writable CD's, Compact Flash and electronic media, any drive/disk or device managed as valid windows pathnames)
duplicate file, synchronize files, synchronize folders, compare files, file compare, backup tools, compare folders, foldermatch, synchronize computers, duplicate file,

 4)   PowerFolder 3.0.0
PowerFolder is a free tool to synchronize,backup,transfer,access and share files over the internet or local network. It can be used to exchange every type of data, for example - documents, photos, music, videos or project files.
powerfolder, synchronization, synchronize folders, synchronize directories, synchronize archives, synchronize files, share folders, share directories, share archives, share files,