This project maintains a list of directories and files you probably do not need to back up, which you can pass to the rsync command's --exclude-from option.

Copycat is a cross-platform file synchronization tool for local file systems similar to robocopy on Windows.

This application performs file synchronization between an Android device and a PC/NAS via wireless LAN using SMB v1/v2/v3 protocol.

Vdirsyncer is a command-line tool for synchronizing calendars and addressbooks between a variety of servers and the local filesystem.

Trilium Notes is a hierarchical note taking application with focus on building large personal knowledge bases.

DSynchronize is a stand-alone utility that let you periodically synchronize two or more folders on Hard Disk, Floppy Disk, LAN, USB Key, CD-DVD and FTP server.

Backup and synchronize tool for Windows 10 (32 & 64 bit), Win8, Win7, Vista, Win XP, Win 2000, Linux (Wine).