Server-based RDF Gateway 1.0 moves semantic Web closer to reality.
Intellidimension Inc.s RDF Gateway 1.0 is one of the first applications to address the use of the Resource Description Framework standard, which makes it possible to have metadata interoperate across Web sites and enable everything from powerful search agents to extensive cross-site agent applications.
RDF is also the core technology behind the World Wide Web Consortiums semantic Web project, whose goal is to build a Web where the meaning of Web content is understandable to machines. However, adoption of RDF has been slow, especially when compared with XML, on which RDF is based.
This is where RDF Gateway, released last month, comes in by providing a powerful server-based system for creating, deploying and managing RDF applications. In tests, eWEEK Labs used RDF Gateway to build a wide variety of Web applications that incorporated and understood RDF, providing a level of content interactivity that would be the envy of most enterprise portals and Web services.
RDF Gateway runs as an all-in-one Web server, application server and database, with the database designed to handle RDF content. This works well and makes the product easy to deploy, but we would prefer a more modular approach that would make it possible, for example, to use the database in conjunction with another Web server and application server.
Pricing for RDF Gateway 1.0 starts at $90 for a personal workstation version and $895 for a server installation. The product is free for academic use. However, RDF Gateway runs only on Windows platforms, making it less attractive to sites that would prefer a Unix-based option.
To develop applications to run on RDF Gateway, we had to code them as RSP (RDF Server Pages), a format developed for RDF Gateway by Intellidimension. Anyone who has worked in other dynamic Web scripting languages, especially Active Server Pages, will find learning and coding in RSP to be a simple task. Still, wed prefer an embedded code model that would make it possible for us to work in the scripting language of our choice.
Administration of RDF Gateway is done through a simple browser-based interface that let us manage content on the server, assign users to the server and create usage roles. We could manage RDF applications, which are added to the server as packages, and could also control "timers," which are server-based controls that handle events.
A Windows-based query tool allowed us to access the database and create and test server-side scripts. Server-side scripts are written in RDF Query Language, which, being based on ECMAScript, was easy to use.
The sample applications that Intellidimension provides on its site were a great help in developing for RDF Gateway. We especially liked the sample portal package (see screen
), which made it possible to build a powerful, interactive information management portal with a slew of user customization options.
This portal also showed how well RDF Gateway can make use of RSS (RDF Site Summary), probably one of the most common uses of RDF on the Web today. RSS is used by many Web sites to create summaries of their site content that can be easily used for syndication. With this application, it became easy for users to create customizable news sites by combing RSS feeds from a variety of Web and internal sources.
East Coast Technical Director Jim Rapoza can be reached at firstname.lastname@example.org