aria2 is a utility for downloading files. The supported protocols are
HTTP(S), FTP, BitTorrent (DHT, PEX, MSE/PE), and Metalink. It can
download a file from multiple sources/protocols and tries to utilize
your maximum download bandwidth. It even 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.