According to an IBM, "Web services are a new breed of Web application. They are self-contained, self-describing, modular applications that can be published, located, and invoked across the Web. Web services perform functions which can be anything from simple requests to complicated business processes...Once a Web service is deployed, other applications (and other Web services) can discover and invoke the deployed service."

IBM’s note on Web services accepts that the notion of a Web service would have been too inefficient to be interesting a few years ago. But the trends like cheaper bandwidth and storage, more dynamic content, the pervasiveness and diversity of computing devices with different access platforms make the need for an adhesive more important, while at the same time making the costs (bandwidth and storage) less objectionable.

In many big enterprises, which have offices spread over various places, there are already computer programs that integrate say purchasing with supply, manufacturing and marketing such that if something is sold, everybody down the line knows about it more or less instantaneously and can take appropriate actions.

If we look at how computers and networks interact, we have an interesting version of the Hegelian dialectic of knowledge (and thereby progress) being achieved though thesis, anti-thesis and synthesis. Initially, in most organisations, we had the so-called dumb-terminals that used the processing power of a main computer. Over a period of time the paradigm changed and we had PCs powerful enough to take care of the needs of various users and thus the stand-alone PC came in vogue. Now there is a synthesis and the attempt is to harness networking through the Internet for computing.

For this you need a common language or a common set of languages and protocols to be more accurate. Inspired by the common platform of the Internet, developers and big corporations like Sun, Microsoft and Apple, have been working on a strategy which would provide a common platform for building applications that can be delivered as reusable, interoperable services over the Internet and corporate intranets.

XML’s role

A fundamental building block for this has been the Extensible Mark-up Language or XML.

Like HTML, XML is platform independent. Unlike HTML, it does focus on providing a proper, pre-defined format to the user. It is an independent language for representing data which is then presented in the form specified by the device accessing the data at that time.

Thus various devices, such as PC’s or mobile phones, personal digital assistants etc will all be able to access XML content and be able to interpret it according the their own modalities. On the other hand, HTML content needs to be changed in order to give proper formatting for each device. In XML, you make changes at the backend and this is reflected in the presentation in various kinds of accessing devices. Thus the time and energy saved using XML is a major obvious gain. The mainstay of the Internet Hyper Text HTTP continues to play an important role though the new alphabet soup includes UDDI (Universal Description, Discovery, and Integration), SOAP (Simple Object Access Protocol), and WSDL (Web Services Description Language).

As Tom Sullivan explained in a much-quoted article, a company offering a particular service would describe it with WSDL then register it with a directory, such as UDDI. A user in need of that service would look it up in the directory and access it using XML and SOAP. For instance, a company conducting international commerce can access a service that approves global tariffs without having to own the tariff application or even subscribe to it (see diagram).

The notion of distributed computing through networks has been an old one and Sun computers used the slogan "the network is the computer," for years. Its Java language was also aimed at providing system-independent Web services and the Unix environment also provided much of what Web services promise—a collection of distributed hardware and software working together.

But with the launch of Visual Studio.NET last week, Microsoft has again managed to capitalise on an established trend. This next-generation suite for people who build software applications supports 20 programming languages, including Microsoft’s new C# (pronounced C-sharp), and gives fairly easy-to-use features that even people who are not hard-core programmers can use.

This would seem to help bring such programming to an ease-of-use level where ordinary computer users would be able to use the program. A rough analogy would be the ease-of-use that HTML programs like Dreamweaver and Front Page have brought in a realm previously dominated by HTML codes and programmers. Now practically anyone who knows how to use MS Word can make Web pages.

According to Microsoft, "The new features of Visual Studio.NET make it a complete development environment for building on the Microsoft .NET Framework, Microsoft’s next generation Web application development platform. It provides key enabling technologies to simplify the creation, deployment, and ongoing evolution of secure, scalable, highly available Web applications and Web services while leveraging developer skills. In addition, the framework provides features to help Web developers use Web services as if they were local objects in the developers’ preferred development language to simplify service and app development. Developers will focus their time and efforts on the unique services that give their company a competitive advantage. The result is faster time to market, improved developer productivity, and ultimately higher quality software."

No doubt this sounds good, but there are clouds of disquiet. Microsoft is not the only player in this game. Other big ones include Bowstreet, Hewlett Packard, IBM, Sun and Oracle.

They are also working on perfecting their solution and taking up this issue whether all these solutions will work well with each other just as HTML applications do. Sun Microsystems is due to launch its Sun One Web services. It is based on Sun’s Java 2 Enterprise Edition platform, as is IBM WebSphere, and it remains to be seen how well the traditional rivals and Microsoft work with each other.

Another thing that is causing concern is the issue of who will control the protocols that govern the networks. We have to remember that the Internet works fairly seamlessly because of the fact that the protocols laid out by the World Wide Web Consortium (W3C) are followed by all concerned.

However, on the issue of Web services, some developers and big companies have held that W3C is dragging its feet in hammering out new protocols. Why are these new protocols so important? Because in the absence of these, developers and vendors may use solutions that are based on non-standard specifications. As a result of this, cross platform accesses would be compromised.

In fact, it was only last week that Microsoft, IBM, BEA Systems and Intel launched the Web Services Interoperability Organisation (WS-I) consortium. Although publicly WS-I and the W3C insist that the two groups will work hand in hand, media reports contend that the relations between the W3C and the tech giants, including Microsoft and IBM, have been growing tense in recent months. This puts the entire effort to develop seamless applications across the Net under a cloud.

However, though there are common points, of concern are the signs of rift as can be seen in the way in which both IBM and Microsoft have launched competing platforms for work flow management —Web Services Flow and Xlang respectively.

This does not augur well for developing truly great Web services. The platform is there, as are most of the protocols, now the players have to get into the spirit of the game to make this holy grail of computing a reality not only for big businesses but across the board, thus moving towards a time when popular applications will be available over the Net.