OpenTaste is a open protocol standard based on OAuth and OpenID that enables the markup of preference semantics in RDF/XML, XML, and HTML with microformats.
Abstract from OpenTaste Profile Semantics spec
"(OpenTaste Profiles implement) a formal semantic specification for describing an individual's preferences for specific items and classes of items. The intent is to provide a semantic framework for expressing preference profiles that can be marked up in an explicit, portable form for interchange between an individuals, profile provider services, and profile consumer services. With it's focus on the semantics of a preference profile, (the) OpenTaste Profile specification is written to be markup language agnostic."
A formal definition of an OpenTaste Profile
In the course of any purposeful behavior, we continually make choices. For our purposes, we may also assume that for each choice we select from an enumerable, although not necessarily finite, set of alternatives. We borrow the notion of a (random) experiment from probability theory and refer to the set of all possible alternatives available to us along with our relative preference for each alternative as a choice experiment, or just a formal choice. We refer to the selected alternative as a choice event, or just an event. An OpenTaste profile is a description of an individual's relative preferences for the alternatives in a choice experiment.
APML and OpenTaste
APML is an XML markup language for one type of personal data: attention. OpenTaste profiles involve much more than that.
OpenTaste is focused on the semantics of taste information needed to make personalized recommendations. Those semantics can be marked up in RDF/XML, XML, and HTML with microformats. The OpenTaste XML dialect strives to maintain the conceptual simplicity of APML, and in fact incorporates the syntax of the body of APML 0.6 XML documents for attention information. Services for providing OpenTaste profiles can accept and serve APML as an alternative exchange format for the attention component of OpenTaste semantics.
Web-scale profile sharing - OT Service Providers
OpenTaste Service Providers are repositories for storing and sharing OpenTaste profile documents under control of the OpenTaste profile owner. OpenTaste profile data are most commonly marked up in OpenTaste XML documents, but OpenTaste Service Providers may also store and share RDF/XML and HTML with microformats OpenTaste profile documents
The OpenTaste Service Provider protocol is based on the OAuth protocol for access delegation and supports the OpenID protocol for access authorization.
