PublishedCloudloop is a new open source Java API and command-line management tool for cloud storage.
Cloudloop provides several advantages over other cloud storage API’s and tools:
(1) Abstracts away differences between different vendors’ interfaces, allowing you to easily switch providers without changing any code.
(2) Allows you to copy data across providers, giving you the ability to synchronize and migrate data between providers.
(3) Provides a file-system-like interface with folders (rather than the primitive key-value system interface used by S3 and other providers).
(4) Supports many varieties of encryption out of the box.
More details at http://wiki.java.net/bin/view/Projects/CloudloopWiki