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.
Rateless-coded Transport is a set of applications that use ground-breaking error correcting codes technology. They support fast reliable transmission over UDP, live content streaming and Internet multicast trees, duplex firewall transparency, ultra-fast reliable transport for WANs (up to 40-times faster than TCP), and optimal peer-to-peer multi-source download protocols.
pftp allows you to send and receive files and directories recursively, send and receive standard input and ouput, filter your connection, set the net buffer size, set the bandwidth, send UDP datagrams unicasted, broadcasted, and multicasted (which is meant for AUDIO and VIDEO streaming), send data to another user and manage that data, perform a network test based on either UDP or TCP, and use optimized buffers for your Gigabit Ethernet links. pftp can start from command line, as a daemon, or by inetd. All features are supported for IPv4 and IPv6.