The inspiration for the patent pending technology behind Unilium came from the desire to have a central, reliable place, to store all files without having to rely on a single service provider (like Amazon or Google). As storage capacities of hard drives increase, there's no reason they shouldn't be usable as personal cloud storage in addition to or instead of online storage. Also, online providers come and go, so there should be no reason to explicitly depend on a single provider. Unilium addresses all of these requirements by making storage providers pluggable and creating a virtual file system on top of arbitrary storage. Unilium goes many steps further than simply combining storage; it provides file versioning and a highly reliable design that enables data to be corrupted and still be able to retrieve file data. Compression is supported as is differential compression, so that if the same file is added to the system, no additional storage is used. If only a portion of a file is changed, only the changed regions are added to the storage. Further, Unilium employs smart block technology that enables policy based decisions on how to break up files. For commonly modified files, such as Word documents, they are broken into smaller blocks. While never-changing files, such as mp3 or mp4 files, may be broken into much larger blocks or not at all. Users may add or remove storage as they desire. For example, if a user wants to shift away from Amazon S3, they may add another storage adapter and sync. Afterwards, they may remove the Amazon storage without hurting anything. Above the storage engine is a simple UI that enables users to manage their files in a similar way that they would in a normal Windows explorer UI. The main difference is that files can be sent or retrieved from the cloud. Even if the cloud holds terabytes of data, the user may download only what they need or want. Finally, the Unilium application is designed to be extremely small and fast so it can run everywhere. For those super-geeks, there is cloudcmd included with Unilum which provides the same functionality as Unilum, but from the command-line. At this time, the underlying Unilium technology is in the patent process with 5 corresponding patents in both United States and China. Additionally, the technology has been licensed and is being integrated into other cloud products.