Cover Pages: XML Daily Newslink: Wednesday, 05 March 2008

A Cover Pages Publication http://xml.coverpages.org/
Provided by OASIS and Sponsor Members
Edited by Robin Cover

This issue of XML Daily Newslink is sponsored by:
IBM Corporation http://www.ibm.com

Headlines

W3C RDB2RDF Incubator Group to Study Mapping Relational Data into RDF
Enhancing Residential Gateways: A Semantic OSGi Platform
Microsoft Bets on Atom Publishing Protocol for Web APIs
W3C Last Call Working Drafts for Service Modeling Language (SML) 1.1
Planning a Semantic Web Site
Microsoft's Directory Team Forced to Reconsider Ignored Standards
AOL Opens AIM for Open Source

W3C RDB2RDF Incubator Group to Study Mapping Relational Data into RDF
Staff, W3C Announcement

W3C has announced the creation of a new RDB2RDF Incubator Group sponsored by Oracle, HP, PartnersHealthcare, and OpenLink Software. The RDB2RDF Incubator Group, part of the Incubator Activity, has two chartered initiatives. The first is to examine and classify existing approaches to mapping relational data into RDF, and decide whether standardization is possible and/or necessary in this area and, if so, the direction such standardization could take. The goal is to specify how to generate RDF triples from one or more Relational tables without loss of information. Furher, a default mapping should not be used, but, instead, it should be possible for the the mapping to be customized by the user. The second initiative is to examine and classify existing approaches to mapping OWL classes to Relational data, or, more accurately, SQL queries, moving towards the goal of defining a standard in this area. Each OWL class would be associated with one or more SQL queries which may be run on separate databases. The results from these queries would then be integrated into a single Relational table; this would be transformed into RDF using the approach defined as a result of the first initiative. An important problem to be solved is the mapping of RDB names to RDF/XML names. The RDB2RDF Incubator Group is chartered through February 2009, with Ashok Malhotra (Oracle) serving as XG Chair. Existing work in this area included, for example: Virtuoso, D2RQ, SquirrelRDF, and ongoing investigations at the University of Texas at Austin. Several approaches are documented in the Collection of Accepted Papers from the "W3C Workshop on RDF Access to Relational Databases," held October 25-26, 2007. This work is expected to be used as a starting point for the Incubator Group.

Enhancing Residential Gateways: A Semantic OSGi Platform
Rebeca P. Díaz Redondo, Ana Fernández Vilas (et al.), IEEE Intelligent Systems

The OSGi (Open Service Gateway initiative) service platform specification is the most widely adopted technology for building a control system for the networked home. This article proposes a semantic approach to service discovery that turns OSGi into a semantic OSGi platform. In this new platform, OSGi services describe their properties and capabilities so other software elements in the residential gateway can automatically determine their purpose (semantic discovery) and how to invoke them. Both tasks involve the semantic markup of OSGi services through appropriate ontologies, which is the core of the Semantic Web and, by extension, of our semantic OSGi platform. The OSGi platform consists of a Java virtual machine (JVM), a set of running components called bundles, and an OSGi framework. In OSGi, the minimal unit of functionality is a service. So, a bundle is designed as a set of cooperating services, which any application might discover after the services are published in the OSGi service registry. An OSGi service is defined by a service interface, which specifies the service's public methods and is implemented as a service object, which is owned by, and runs within, a bundle. The bundle registers the service object with the OSGi service registry so its functionality is available to other bundles. In general, registered services are referenced through service reference objects, which maintain the properties and other metainformation about the service. To implement our proposal, we selected the Open Source Container Architecture (OSCAR), an open software implementation of the OSGi framework. To manage the local OWL-OS ontology and provide the proposed semantic OSGi services, we use the Protege OWL API. This open source Java library provides classes and methods to load and save OWL files, query and manipulate OWL data models, and perform reasoning. We implemented a semantic version of the OSCAR registry that interprets the new bundle manifests and manages the OWL-OS ontology to accomplish service registration (populating the ontology) and search (querying the ontology) as described earlier. To include query processing in our framework, we use the OWL-QL toolkit. For reasoning, we used Jess, a rule engine for the Java platform that can reason from knowledge expressed in declarative rules; jessTab is a plug-in for Protege that lets users interact with Jess. By automating OSGi services composition, we open the platform to ambitious applications that rely on the idea that different home services usually form a pool committed to various home activities, such as energy control, security, and healthcare.

Microsoft Bets on Atom Publishing Protocol for Web APIs
Hartmut Wilms, InfoQ

Microsoft is switching from the "Web Structured, Schema'd & Searchable (Web3S)" protocol to the Atom Publishing Protocol (AtomPub) for services offered by Microsoft's Live Platform on the Web. David Treadwell, Corporate Vice President of Microsoft's Live Platform Services, discussing the Windows Live Platform Services, notes that "Microsoft is making a large investment in unifying our developer platform protocols for services on the open, standards-based Atom format (RFC 4287) and the Atom Publishing Protocol (RFC 5023). At MIX we are enabling several new Live services with AtomPub endpoints which enable any HTTP-aware application to easily consume Atom feeds of photos and for unstructured application storage. Or you can use any Atom-aware public tools or libraries, such as .NET WCF Syndication to read or write these cloud service-based feeds." AtomPub will also be used as the standard protocol for ADO.NET Data Services, codename "Project Astoria". According to Dare Obasanjo: "The fact is when we listened to the community of Web developers the feedback was overwhelmingly clear that people would prefer if we worked together with the community to make AtomPub work for the scenarios we felt it wasn't suited for than Microsoft creating a competing proprietary protocol. We listened and now here we are. If you are interested in the technical details of how Microsoft plans to use AtomPub and how we've dealt with the various issues we originally had with the protocol, I suggest subscribing to the Astoria team's blog and check out the various posts on this topic by Pablo Castro..." Adapting the standardized Atom Publishing Protocol is in line with Microsoft's new interoperability principles, support for REST and Syndication in WCF, and the high extensibility and pluggability of the ASP.NET MVC Framework.

See also: the InfoWorld article

W3C Last Call Working Drafts for Service Modeling Language (SML) 1.1
Bhalchandra Pandit, Valentina Popescu, and Virginia Smith (eds), W3C Technical Report

Members of the W3C Service Modeling Language Working Group have published Last Call Working Drafts for "Service Modeling Language, Version 1.1" and "Service Modeling Language Interchange Format, Version 1.1." SML defines extensions to the W3C XML Schema language by adding support for inter-document references and user-defined constraints. This combination of features is very useful in building complex multi-document models that capture structure, constraints, and relationships. In the management domain, these models are typically used to automate configuration, deployment, monitoring, capacity planning, change verification, desired configuration management, root-cause analysis for faults, etc. A "model" in SML is realized as a set of interrelated XML documents. The XML documents contain information about the parts of a service, as well as the constraints that each part must satisfy for the service to function properly. Constraints are captured in two ways: (1) Schemas: defining constraints on the structure and content of the documents in a model. SML uses XML Schema (XML Schema Structures, XML Schema Datatypes) as the schema language. In addition SML defines a set of extensions to XML Schema to support references that may cross document boundaries. (2) Rules: Boolean expressions that constrain the structure and content of documents in a model. SML uses Schematron (ISO/IEC 19757-3, Introduction to Schematron, Improving Validation with Schematron) and W3C XPath for rules. One of the important operations on the model is to establish its validity. This involves checking whether all data in a model satisfies the schemas and rules declared. This specification focuses primarily on defining the extensions to XML Schema for references that cross document boundaries, Schematron usage in SML, as well as the process of model validation. The Last Call review period extends until 26-March-2008.

Planning a Semantic Web Site
Rob Crowther, IBM developerWorks

The Semantic Web brings with it the opportunities for users to get smarter search results, and for site owners to get more targeted traffic as users find what they really want. This article discusses what you need to know to make your Web site part of the Semantic Web. It starts with a discussion of the problems the Semantic Web tries to solve and then moves to the technologies involved, such as Resource Description Framework (RDF), Web Ontology Language (OWL), and SPARQL Protocol and RDF Query Language (SPARQL). You'll see how the Semantic Web is layered on top of the existing Web. It then covers some issues that you want to know about when you plan a new Web site and also gives specific examples of how to use technologies like RDFa and Microformats to enable your existing Web site to become a part of the Semantic Web. Although the promise of Tim Berners-Lee's Semantic Web is yet to be fully realized, the years of thinking and research that have gone into it are starting to bear fruit in terms of solutions to practical problems that people face today. The strong collaboration trends in Web 2.0 will only lead to more requirements for structured and semantically encoded data being available on the Web. With some planning, you can be in position to take advantage of the Semantic Web tools which help meet that need.

See also: the W3C Semantic Web

Microsoft's Directory Team Forced to Reconsider Ignored Standards
John Fontana, Network World

Recent proclamations by Microsoft CEO Steve Ballmer that the company would move toward interoperability and support for standards is putting pressure on the head of the company's directory and identity development to reconsider support for industry standards such as Security Assertion Markup Language (SAML) that have been long ignored. Joe Long, general manager of the connected identity and directory at Microsoft, said during a panel discussion at NetPro's Directory Experts Conference that Microsoft was being forced to re-examine if it would support SAML, the Service Provisioning Markup Language (SPML) and the Extensible Access Control Markup Language (XACML). Microsoft already supports the SAML 1.1 token format but does not support the SAML request/response engine that it is part of the specification. It also does not support SAML 2.0. The Liberty Alliance and the Shibboleth identity project support SAML. Microsoft supports WS-Federation, a specification it created with IBM and sent to OASIS. WS-Federation unlike SAML splits the request/response engine and the token format allowing it to support many token formats. Long's comments came a day before Microsoft's Stuart Kwan took the DEC keynote stage and explained that standards were a key cog in building an "identity bus" for identity systems that applications could plug into.

See also: the 'identity bus'

AOL Opens AIM for Open Source
Sean Michael Kerner, InternetNews.com

For the last two years, AOL has been promoting its OpenAIM initiative as a vehicle to enable developers to build their own AIM (AOL Instant Messenger)-based clients. But there were issues with documentation that got in the way of some projects. With the release of Open AIM 2.0 today, AOL is aiming AIM at open source developers with more ease-of-use tools. Among the major changes in Open AIM 2.0 is the fact that AOL is now providing open documentation on its core OSCAR protocol (Open System for CommunicAtion in Realtime), which powers AIM. Previously, open source instant messaging client implementations of OSCAR had to reverse-engineer the protocol instead of simply using a documented protocol. Although Open AIM 2.0 provides open access to the OSCAR protocols, developers need to do something for AOL in return. AOL requires that developers choose two options from a list of five items that must be added to an Open AIM-based client. The list includes the addition of display ads, a link to include the AIM toolbar, showing AIM buddy icons, displaying AIM buddy information or displaying the AIM start page. Cypes noted that a number of open source AIM implementations already provide the buddy icon and information features so he expects no major issues. In addition to being open with OSCAR, Open AIM 2.0 also lifts the Open AIM 1.0 restriction on multi-headed clients. That is to say, Open AIM will now allow users to build IM clients that support AIM as well as IM protocols from other vendors, including Jabber (XMPP), Yahoo, and Microsoft.


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