Downloading DirSyncPro unknown from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. We recommend checking the downloaded files with any free antivirus. This free program was originally produced by DirSyncPro. The program belongs to System Utilities.
From the developer:
DirSync Pro (Directory Synchronize Pro) is a small, but powerful utility for file and folder synchronization. DirSync Pro can be used to synchronize the content of one or many folders recursively.
Using DirSync Pro you can make incremental backups. In this way you'll spare lots of time because you don't have to copy all the files each time you want to update your backup; only new/modified/larger files would be copied.
You may want to check out more software, such as Document Backup by Insofta Development, AISBackup or BackRex Outlook Backup, which might be related to DirSyncPro.