SyncServer

SyncServer is a mirroring tool for Windows servers. It allows you to set up a master and a slave so that there is always a continous one-way traffic to either backup data, or create redundant servers without having to restore from media backup. Whatever the reason you would need to sync two servers together, SyncServer could be your key if you’re running Windows machines.
Using a custom port, it creates a one-way traffic pattern and the master initiates contact based on the configuration that you give it (scheduled time, etc). The slave listens in the background continuously for the master to send commands. When it (the master) does, it checks changed or deleted files, and sends the commands to upload and delete whatever files to create a totally mirror copy of the master server. Passwords are used to protect access, while md5 hashes are used to make sure that the transferred files are the same. Open source for Windows.