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.
TurnKey Torrent Server Appliance is a file server appliance with integrated multi-protocol file sharing that can be used to handle all types of file downloads. Files can be added to the download list using the Torrent Server handler extension for Firefox or through a simple Web interface that allows you to manage the server remotely. It is especially useful for centralizing file sharing on a shared network. Anti-virus scanning is included.
Btpd is a utility for sharing files over the BitTorrent network protocol. It runs in daemon mode, thus needing no controlling terminal or GUI. Instead, the daemon is controlled by the btcli command line utility or other programs capable of sending commands and queries on the btpd control socket.