Most people’s downloads are done via an FTP client, a Web browser, or a file-sharing program like BitTorrent. These means of downloading files will probably never change, but the tools to do the downloading, and how they download, will.
One program that changes how files are downloaded is Aria2. Aria2 is a lightweight multiprotocol and multisource download utility that offers some very compelling reasons for its use over traditional “single thread” downloading such as with an FTP or HTTP client.
Being a multiprotocol client, Aria2 can download via HTTP, via FTP, and via BitTorrent. What makes Aria2 unique is that it can download the same file at the same time utilizing different protocols. It can also open multiple connections to the same, or different, URLs to download the file even faster. By default, Aria2 uses five connections to download a file.
aria2 is a lightweight multi-protocol & multi-source, cross platform download utility operated in command-line. It supports HTTP/HTTPS, FTP, BitTorrent and Metalink.
aria2 has built-in XML-RPC interface. You can manipulate aria2 via XML-RPC interface.
aria2 can download a file from multiple sources/protocols and tries to utilize your maximum download bandwidth. Really speeds up your download experience.
aria2 doesn’t require much memory and CPU time. The physical memory usage is typically 4MiB (normal HTTP/FTP downloads) to 9MiB (BitTorrent downloads). CPU usage in BitTorrent with download speed of 2.8MiB/sec is around 6%.
Fully Featured BitTorrent Client
All features you want in BitTorrent client are available: DHT, PEX, Encryption, Magnet URI, Web-Seeding, Selective Downloads and Local Peer Discovery.
aria2 supports The Metalink Download Description Format(aka Metalink v4). Old Metalink v3 is also supported. Metalink offers File verification, HTTP/FTP/BitTorrent integration and Configuration for language, location, OS, etc
Command-line scares you off? No, aria2 is really easy to use!!
Download from WEB
Download from 2 sources
BitTorrent Magnet URI
Download URIs found in text file
The speed gains of Aria2 are incredible. If BitTorrent isn’t your thing,
imagine finding five different mirrors of your favorite Linux distribution
and passing the URLs to Aria2. Possibly the longest part of that would be finding
the URLs and pasting it to the command-line, rather than the actual downloading.