SYNC Commander is a backup / synchronization tool supporting file system to file system, FTP to file system, file system to FTP copy, update and sync. 2 folders with 750+ sub-folders, 260000+ files and 14 GB+ total is sync by it everyday on my servers.
UltraCommander is a multi-user remote file manager you can use through your web browser. It is designed for Linux/UNIX based servers, although it should work on M$ Windows. UC allows you to upload, download, manage, view, run remote files.