The Personal Cloud paradigm emerges as a decentralized and privacy preserving solution to manage personal documents under users’ control. It can be seen as an alternative to the current Web model, which centralizes the complete digital life of millions of individuals in data silos, and increases frustration generated by the weak control of the individuals on the way their personal data are shared, used and disseminated. The home cloud is the most emblematic form of Personal Cloud. It can be thought of as a dedicated box connected to the user's internet gateway, equipped with storage, computing and communication facilities, running a personal server and acquiring data from multiple sources. This personal server is in charge of organizing the personal dataspace in a document database style to ease its management and to protect it against loss, theft and abusive use. Many startups (e.g., OwnCloud, CozyCloud, etc.) and research projects (e.g., PlugDB at Inria or OpenPDS at MIT) investigate this direction.