Arq

Arq is super-easy online backup for Mac and Windows computers. Back up to your own cloud account (Amazon Cloud Drive, Google Drive, Dropbox, OneDrive, Google Cloud Storage, any S3-compatible server), your SFTP server, or your NAS. On OS X, Arq backs up and faithfully restores all the special metadata of Mac files that other products don't, including resource forks, ACLs, and creator codes. Following the initial backup, Arq automatically makes incremental backups every hour, every day, uploading just the files that have changed since your last backup. Arq keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for everything older than a month. Arq lets you set a budget for storage, and it automatically drops the oldest backups to keep within the budget. Arq backs up everything with no limits. It backs up files of any size, external drives, and network drives. Arq compresses and "de-duplicates" your backups, never storing the same file twice in the cloud. Arq encrypts all your backups with a password that never leaves your computer, so no one can read your cloud backups. You can back up to multiple accounts. Back up some files to Glacier, some to S3, some to an SFTP server, etc. Additional plans, which include storage and additional features, are available.