aria2: high speed command line download utility
If you’re a frequent downloader and comfortable on the command line, then you need to try out aria2. aria2 is a cross platform download utility, similar to graphical download managers except that it uses less system resources.
aria2 has a number of invaluable features such as download resuming, BitTorrent and Metalink support, segmented downloading, downloading a single file from one or multiple servers (including integrated BitTorrent and HTTP/FTP transfers), downloading many files at the same time, automatic error recovery/repair (BitTorrent and Metalink downloads only), etc.
aria2 is a command line application, but don’t let that scare you off. You can use aria2fe, a graphical front end, if that makes you more comfortable.