aria2 is a lightweight multi-protocol & multi-source command-line download utility. It supports HTTP/HTTPS, FTP, SFTP, BitTorrent and Metalink, etc.
License: Open Source
Aria2 is a versatile command-line tool that supports multiple download protocols and is highly configurable, making it ideal for advanced users. In contrast, PicoTorrent is a lightweight torrent client with a user-friendly interface designed specifically for torrenting, making it more accessible for casual users.