Unison is a file-synchronization tool for OSX, Unix, and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other. Developed by Benjamin C. Pierce
License: Open Source
SyncToy is a freeware tool in Microsofts PowerToys series that provides an easy-to-use graphical user interface for synchronizing files and folders in Windows versions XP, Vista and 7. It is written using Microsofts .NET framework and uses the Microsoft Sync Framework. Developed by Microsoft
License: Free
Unison is a powerful file synchronization tool offering real-time syncing, version control, and cross-platform support, making it ideal for advanced users and complex sync tasks. SyncToy, on the other hand, is a user-friendly Windows-only application focused on simplicity and scheduled syncs, suitable for casual users requiring basic file synchronization.