[rclone](https://rclone.org/) is a command line program to sync files and
directories to and from a vast variety of cloud provider and protocols. At
the time of writing, this includes the following services:

  * Amazon S3 / Dreamhost / Ceph / Minio / Wasabi
  * Backblaze B2
  * Box
  * Dropbox
  * FTP
  * Google Cloud Storage
  * Google Drive
  * HTTP
  * Hubic
  * Jottacloud
  * Mega
  * Microsoft Azure Blob Storage
  * Microsoft OneDrive
  * OpenDrive
  * Openstack Swift / Rackspace cloud files / Memset Memstore / OVH / Oracle Cloud Storage
  * pCloud
  * QingStor
  * SFTP
  * Webdav / Owncloud / Nextcloud
  * Yandex Disk
  * The local filesystem

That list is regularly expanding. git-annex supports all of those through
the use of the [rclone special remote](https://github.com/DanielDent/git-annex-remote-rclone).

See their documentation for more concrete examples.