Personal data services or personal data stores (PDS) are services to let an individual store, manage and deploy their key personal data in a highly secure and structured way. They give the user a central point of control for their personal information (e.g. interests, contact information, affiliations, preferences, friends). The user's data attributes being managed by the service may be stored in a co-located repository, or they may be stored in multiple external distributed repositories, or a combination of both. Attributes from a PDS may be accessed via an API. Users of the same PDS instance may be allowed to selectively share sets of attributes with other users. A data ecosystem is developing where such sharing among projects or "operators" may become practicable.