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
Persepolis Download Manager offers a user-friendly experience with features like download scheduling and good integration with browsers, making it ideal for casual users. In contrast, aria2 is a powerful command-line tool that supports various protocols including BitTorrent, making it suitable for advanced users who prefer automation and customization.