Rclone
Rclone (via Felix Schwarz):
Rclone is a command line program to sync files and directories to and from:
- Google Drive
- Amazon S3
- Openstack Swift / Rackspace cloud files / Memset Memstore
- Dropbox
- Google Cloud Storage
- Amazon Drive
- Microsoft OneDrive
- Hubic
- Backblaze B2
- Yandex Disk
- SFTP
- The local filesystem
There’s also an interesting overview of the features of the different cloud storage systems.
For what its worth, I recently had a lot of issues with this tool and Amazon Drive. Not Rclone's fault in the slightest (Amazon shut down the access), but perhaps worth heeding as a warning before getting too invested.
https://forum.rclone.org/t/rclone-has-been-banned-from-amazon-drive/2314/360
One of the larger use cases for Rclone recently has been to get huge Plex video libraries into the cloud for use with Plex cloud, which not surprisingly has caught the attention of most of the major cloud storage providers. As you might imagine, they aren't too keen on hosting TB's of video on individual "unlimited" storage plans.
I've had various issues with Google Drive related to their API's request throttling as well. For google Drive anyway, this project has been much more reliable.
https://github.com/astrada/google-drive-ocamlfuse
At any rate, Dropbox, Google and Amazon etc seem to be engaged in cat and mouse games to try and limit what people do with their consumer storage offering APIs.