Move files from one file system scheme (e.g., public://) to another (e.g., s3://) during cron runs, using queues. Supports checking dependencies (like whether image style derivatives or converted videos exist) before moving files.
The main goal is to allow image and video files to be processed on the local public:// system for performance, and then moved at a later time to Amazon S3 where storage is cheaper and more abundant. But theoretically it could be used to move files to any other file system scheme so long as you have a stream wrapper implementation for it.