lftp is sophisticated file transfer program with command line interface. It supports FTP, HTTP, FISH, SFTP and FILE (local FS) protocols. GNU Readline library is used for input. BitTorrent protocol is supported as built-in torrent command.
Low level stuff supported: ftp proxy, http proxy, ftp over http, opie/skey, fxp transfers, automatic retrying on non-fatal errors and timeouts, ipv6, socks, http/1.1, sftp v3-v6.