As is the case with many Web technologies today, nearly every core piece of the Semantic Web is based on XML, from RDF to OWL to SPARQL.
This means that, for the most part, all it takes to build things for the Semantic Web is a good text editor. However, to be truly productive at working on Semantic Web applications, most would agree that dedicated tools are the way to go.
There have been a number of simple and free prototype tools built by World Wide Web Consortium members, such as the Tabulator, a simple tool that makes it possible to browse through complex Resource Description Framework data directly from a standard Web browser.
But for companies those looking for commercial Semantic Web products, the market is finally beginning to gain steam as more vendors from the traditional Web and Web service development, search, data analysis and management fields are releasing products dedicated to creating and managing applications and data for the Semantic Web.
eWEEK Labs took a look at three products designed to help businesses build and manage Semantic Web solutions: Altovas SemanticWorks 2007, Intellidimensions RDF Gateway 2.3.4 and TopQuadrants TopBraid Composer 2.0. All three of these programs are available in free evaluation versions and are worth checking out for any business interested in building Semantic Web solutions.
Altovas SemanticWorks 2007 is a Windows-based visual RDF and OWL (Web Ontology Language) editor. Altova has long been a strong player in the XML development market and anyone who has used its excellent XMLSpy XML development tool will instantly feel at home in SemanticWorks 2007.
With this tool we could create and edit RDF data files and OWL ontologies using a visual data map to control all of our core data relationships and definitions. We appreciated the visual tools but liked even more that we could quickly jump out of them to a standard code view of our files.
SemanticWorks 2007 provided tools to check the validity of our syntax and semantic code and offered good feedback on errors or inconsistencies. Another nice touch let us save our OWL mappings as images, which made it possible to display ontology information in collaborative settings.
Altova SemanticWorks 2007 is priced at $129 and can be found at www.altova.com.
RDF Gateway 2.3.4
Intellidimensions RDF Gateway was one of the first true Semantic Web products that we ever tested here at eWEEK Labs, when we evaluated version 1.0 in 2003. From our recent tests of version 2.3.4, it doesnt look like much has changed—not that this is a bad thing. RDF Gateway is still a solid combination of a Web server, application server and RDF gateway and is still a good way to get Semantic Web applications up and running.
However, it also remains a Windows-only application, and the product also still uses its own Web scripting language known as RDF Server Pages (which are simple to create for anyone who has used Java Server Pages or similar languages).
Most of the main improvements in RDF Gateway are in upgraded support for newer standards. RDF Gateway ships with its own ECMAScript-based query language called RDF Query Language, but it also now supports SPARQL (SPARQL Protocol and RDF Query Language).
A simple Windows querying tool included with RDF Gateway made it possible for us to create, test and deploy applications for the RDF Gateway server.
The products setup wizards stepped us through deploying and running applications, and its browser-based administration interface enabled us to manage the server and control access and permissions.
Intellidimension offers a free personal version of RDF Gateway, as well as a professional edition that starts at $595, and an enterprise edition that starts at $1,995. For more information go to www.intellidimension.com.
TopBraid Composer 2.0
As with many other applications today that have anything to do with creating Web applications or Web services, TopQuadrants TopBraid Composer 2.0 is an Eclipse-based development tool. By far the main strength of TopBraid Composer is in ontology development and editing.
We were greatly impressed with the depth of capability that TopBraid Composer gave us for visually designing complex OWL ontologies.
The way TopBraid Composer laid everything out made it surprisingly easy to get a grasp on complex semantic applications. When editing an OWL file we could quickly view and configure it in multiple ways, with easy access to core settings, parameters and SPARQL queries with syntax checking.
We could switch quickly between multiple viewing formats, including a very good visual diagram, an RDF graph, a form-based window and a well-implemented source-code view.
TopBraid Composer also does a good job of utilizing and supporting a wide variety of newer Semantic Web standards and draft or proposed standards, such as SWRL (Semantic Web Rule Language) and GRDDL (Gleaning Resource Descriptions from Dialects of Languages).
TopBraid Composer is priced starting at $495 and can be found here.
Chief Technology Analyst Jim Rapoza can be reached at [email protected]