"rsync for cloud storage" - Google Drive, Amazon Drive, S3, Dropbox, Backblaze B2, One Drive, Swift, Hubic, Cloudfiles, Google Cloud Storage, Yandex Files
A command line tool and library for transferring data with URL syntax, supporting HTTP, HTTPS, FTP, FTPS, GOPHER, TFTP, SCP, SFTP, SMB, TELNET, DICT, LDAP, LDAPS, MQTT, FILE, IMAP, SMTP, POP3, RTSP and RTMP. libcurl offers a myriad of powerful features
aria2 is a lightweight multi-protocol & multi-source, cross platform download utility operated in command-line. It supports HTTP/HTTPS, FTP, SFTP, BitTorrent and Metalink.