--stream-piece-selector=inorder
Very useful to start watching a video file before its fully downloaded. It must be the most advanced downloader.
http://aria2.sourceforge.net/manual/en/html/aria2c.html#cmdo...
I hacked axel to do the same but my patch was not perfect. https://github.com/adrenalinup/axel-incremental-downloading
Didn't knew that aria2 provided this out-of-the-box.