CopyQueue - CopyQueue - Copying under control.

GoodSync - GoodSync provides highly reliable file backup and synchronization for both individuals and businesses.

MirrorFolder - MirrorFolder is a real-time folder synchronization and backup software

rsync - rsync is a file transfer program for Unix systems. rsync uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync.

PuTTY - Popular free terminal application. Mostly used as an SSH client.

FreeFileSync - FreeFileSync is a free open source data backup software that helps you synchronize files and folders on Windows, Linux and macOS.