People sometimes ask me about where and how personal data is stored in CloudOS. The "personal data service" or PDS is the foundational element in CloudOS that handles personal data. But it's not a data store so much as a consistent API to where ever the owner of the cloud wants to keep their data.
People sometimes ask me about where and how personal data is stored in CloudOS (the foundation of SquareTag). CloudOS provides as one of it's core services a personal data service. If you click the gear menu in myApps, you'll see a way to access your services. We keep them out of the way so people don't accidentally delete or disable them. Think of "services" like /usr/lib in Linux.
You'll notice the PDS service listed there with an icon that has a little database symbol.
The CloudOS PDS service isn't meant to be standalone data store although it can function that way. Our plan has always been to have the PDS service provide a consistent programmer interface (in the original meaning of API) to whatever data the user cares about where ever it might be stored.
You could imagine things like openPDS or personal.com serving as a foundational store for the CloudOS PDS without applications needing to understand or know their specific APIs. I recently demonstrated how Dropbox can be linked into CloudOS. The PDS could provide a consistent API for some or all of these.
We are currently exploring, together with Neustar and Respect Network, putting the XDI2 server inside the PDS, a project I call PDSx. Using an XDI-based platform as the basis for personal data stored has significant advantages for sharing and permissioning data interchange. There's also a strong interoperability play. PDSx is an experiment in using XDI in a production environment and one that I believe is worthy of our time and effort. Watch this space for updates.