WinSCP is a free SFTP, SCP, S3, WebDAV, and FTP client for Windows.
WinSCP is a popular free filemanager for Windows supporting SFTP, FTP, FTPS, SCP, S3, WebDAV and local-to-local file transfers. A powerful tool to enhance your productivity with a user-friendly interface and automation options like .NET assembly or batch file scripting. Use WinSCP also for file editing, directory synchronization and site management. WinSCP is open-source and well documented.
PeerProject is a versatile peer-to-peer filesharing client and filemanager. Intuitive and aesthetic while supporting many networks and features. BitTorrent, G2, Gnutella, eDonkey, DC++, IRC, http/ftp & more. Mainstream fork of Shareaza p2p, for Windows & WINE.
Note: This project is idle, see Envy fork for further development.
Giau ten is a 3rd generation filesharing system which is developed by some students.
It will be extremly modular so every thing can changed by others or you can replace for example the gui if you like a other one more.