Top 4 robocopy open source projects

Get folder sizes blazingly fast with PowerShell

Windows service for orchestrating file backups via robocopy utility.

Right Click Windows Magic is an open-source set of right-click (context) menu tools for admins, power users and other magic beings. Batch&Powershell.

Folder Monitor is a windows service for sync files and folders with nice GUI, it uses the robocopy tool.