XML News from Saturday, July 7, 2007

The W3C Web Services Activity has published proposed recommendations of Web Services Policy 1.5 - Framework and Web Services Policy 1.5 - Attachment. According to the former,

Web Services Policy 1.5 - Framework defines a framework and a model for expressing policies that refer to domain-specific capabilities, requirements, and general characteristics of entities in a Web services-based system.

A policy is a collection of policy alternatives. A policy alternative is a collection of policy assertions. A policy assertion represents a requirement, capability, or other property of a behavior. A policy expression is an XML Infoset representation of its policy, either in a normal form or in its equivalent compact form. Some policy assertions specify traditional requirements and capabilities that will manifest themselves in the messages exchanged(e.g., authentication scheme, transport protocol selection). Other policy assertions have no wire manifestation in the messages exchanged, yet are relevant to service selection and usage (e.g., privacy policy, QoS characteristics). Web Services Policy 1.5 - Framework provides a single policy language to allow both kinds of assertions to be expressed and evaluated in a consistent manner.

Web Services Policy 1.5 - Framework does not cover discovery of policy, policy scopes and subjects, or their respective attachment mechanisms. A policy attachment is a mechanism for associating policy with one or more policy scopes. A policy scope is a collection of policy subjects to which a policy applies. A policy subject is an entity (e.g., an endpoint, message, resource, interaction) with which a policy can be associated. Web Services Policy 1.5 - Attachment [Web Services Policy Attachment] defines such policy attachment mechanisms, especially for associating policy with arbitrary XML elements [XML 1.0], WSDL artifacts [WSDL 1.1, WSDL 2.0 Core Language], and UDDI elements [UDDI API 2.0, UDDI Data Structure 2.0, UDDI 3.0]. Other specifications are free to define either extensions to the mechanisms defined in Web Services Policy 1.5 - Attachment [Web Services Policy Attachment], or additional mechanisms not covered by Web Services Policy 1.5 - Attachment [Web Services Policy Attachment], for purposes of associating policy with policy scopes and subjects.


Steve Palmer has released Vienna 2.1.3.2111, an open source RSS/Atom client for Mac OS X. Vienna is the first reader I've found acceptable for daily use; not great but good enough. (Of course my standards for "good enough" are pretty high.) This is a bug fix release.