FileZilla is a fast and reliable FTP client and server with lots of useful features and an intuitive interface.

JFtp is a graphical Java network and file transfer client.
It supports FTP using its own FTP API and various other protocols like SMB, SFTP, NFS, HTTP, and file I/O using third party APIs, includes many advanced features such as recursive directory up/download, browsing FTP servers while transferring files, FTP resuming and queueing, browsing the LAN for Windows shares, and more.