TFTP Server is a multi-threaded TFTP server, allowing any number of clients to connect simultaneously. It supports tsize, blksize, and interval options, PXE boot, and can be run standalone or as a daemon. Port ranges can be specified to work across firewalls. There is also a single port version, for situations where additional ports cannot be opened.
aria2 is a utility for downloading files. The supported protocols are HTTP(S), FTP, BitTorrent, and Metalink. It has a powerful segmented downloading ability, downloading a file from multiple sources and multiple protocols and utilizing your download bandwidth to the maximum. It supports downloading a file from HTTP(S)/FTP and BitTorrent at the same time, while the data downloaded from HTTP(S)/FTP is uploaded to the BitTorrent swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like BitTorrent.
kio-ftps is an FTPS KIO slave for KDE. It implements secure FTP sessions based on RFC 4217 and built upon the FTP KIO-slave sources. It should work with most server implementations. It issues an "AUTH TLS" command after connecting and refuses to continue when it's not supported. Prior to every data channel I/O command ("STOR", "RETR", etc.) it tries to secure the data channel via "PBSZ" and "PROT" commands. If that fails, it will transfer data unencrypted. There is currently no support for SSL certificates.