rsync, FreeFileSync, SyncBack, GoodSync, Allway Sync, Bacula, ChronoSync, lsyncd, DirSync Pro, PureSync, grsync, Unison File Synchronizer, Toucan, FullSync, FBackup, Backer, Bvckup 2, BFileSync, MirrorFolder, DSynchronize, Compare Advance, csync, Synkron, OneSync, Directory Compare, Create Synchronicity, SyncFolders, Uranium Backup, Synchredible, cwrsync, ozSync, jaBuT, CompareMerge, Alternate File Move, Bonkey, rsync backup for Android, Folder Sync, OneWaySynchronize, SyncDesk, CopyInOrder, Dmailer Sync, SSuite Kronoz Sync-Master, Backuplist, Sync Butler, Kup Backup System, DiffVue, 7zbackup, CleanSync, JFileSync, AllSync by Michael Thummerer Software Design, Digionica SyncTool, SmartBackup, WinDataReflector, Syncless are some alternatives to SyncToy.