Sync Last Files is a free software to synchronize files between folders. Instead of synchronizing all the files, Sync Last Files synchronizes only those files that have changed. This greatly reduces the speed of synchronization even for large folders.
Another great feature of Sync Last Files is that it can create incremental backups of all the changes. This means you can anytime revert back to a previous version of the file in case you accidentally lost changes. This is an extremely useful feature, and makes Sync Last Files one of the best file synchronization software. Similar versioning feature is also available in Dropbox, and BinFire.
Sync Last Files Free is completely free, and easy to use. You can also check out software to sync folders between Windows and Linux computers.