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.