Accessing web-services. (Storage Management).

Transferring the power of the desktop into an Internet browser environment is the essence of Web services. According to the META Group, "During the next 2-3 years, most packaged business applications and newer custom applications will have fairly complete event-driven interfaces that will be exposed via the Web services model, and Web services creation capability will be an automated part of virtually all development environments."

Today's Web service technologies are being specifically designed to enhance the Internet strategies of the enterprise. The promise of Web Services is to allow enterprise-level computing with suppliers, partners and customers in a powerful, familiar and easy-to-use medium. With Web applications built on the Web services model, important business contacts can simply access enterprise Web applications the same way they would any other Web site. Once there, they'll then be treated to a dynamic user experience that mirrors a traditional desktop-computing environment--or will they? In the Web Services creation process, today's IT professionals are struggling to determine the most appropriate method of accessing Web Services and creating usable Web applications. Currently, the three primary choices include:

1. HTML-based Delivery

2. Applet and Plug-in Delivery

3. "Rich-thin Client" Delivery

HTML: The Road Less Traveled

HTML alone is incapable of delivering usable Web applications or directly accessing a Web Service. Browser application technologies have evolved significantly since their inception. Originally, the government and educational institutions designed the Web to share "linked" documents. The Web was never intended to handle the complexities of enterprise computing and business processing as an application platform. HTML forms were the earliest Web applications to appear--providing a limited set of crude user interface components. Because of their underlying structure, HTML forms forced users to navigate through a series of independent Web pages to accomplish the simplest of tasks. Unfortunately, they delivered a halting, frustrating and nonintuitive user experience--costing businesses in lost customers and reduced productivity. Even today, industry vendors are struggling to create Web applications that can successfully deliver dynamic back-end content as sophisticated, front-end presentation using HTML. Even with the advancements in browser technologies, HTML alone simply isn't robust enough to handle the complexities of real-world enterprise computing in a Web Services model.

Inconsistencies and inefficiencies of HTML-based Web applications are both costly and limiting for most enterprises. Early adopters recognized that most end-users were paralyzed by the unfamiliar interface provided by Web applications built on HTML. Because first-generation Web applications relied solely on HTML, even simple tasks would reload the browser with a new Web page after every mouse click-clearly limiting business productivity. For these reasons, the full adoption of Web application computing was severely derailed for a time. However, HTML forms did act as the impetus for the next evolutionary Web technology: Java applets and custom browser plug-ins.

Applets: Plugging into the Next Best Thing

Applets and Plug-ins are capable of delivering rich Web applications, but at high cost to the enterprise and the end-user. Java applets and other custom plug-ins were developed to enhance end-user interaction within a Web page--successfully overcoming most of the obstacles associated with HTML forms. Java applets allowed developers to deliver real client applications within the browser. The resulting Web applications were much more functional than HTML forms had been; however, serious issues quickly emerged with applet and plug-in delivery.

As newer versions of Java entered the market, they were not automatically incorporated into the browser, forcing users and/or administrators to assume the burden of client/server-like maintenance and upgrade issues. And although simple applets performed well, large and complex business applications built on applets were unresponsive, sluggish and did not meet user performance expectations.

Deeper technical issues have also plagued Java in the browser. These issues include paint and refresh problems (evident by screen flickers), lack of a rich widget set and inconsistent views across multiple operating environments like Linux, Mac and Windows (relying heavily on the operating system widgets).

Although technically functional, the broad use of Java applets, as a means of accessing Web Services, hasn't captured total market attention and has fallen out of favor with both developers and enterprise managers alike. However, Java applets did invigorate the tech industry's imagination on what was possible in a browser environment.

Another effort to deliver fast, graphic-intensive Web applications was lead by Macromedia's proprietary technologies--Flash and Shockwave. These were added to the browser as platform-specific plug-ins that, like Java, required new development skills and methodologies. Unlike Java, Flash and Shockwave have been extremely successful in enhancing the user experience but have not provided a true "Browser Application Platform." Flash enjoys great market acceptance as a multimedia environment; however, despite recent efforts, questions remain on whether enterprise developers will adopt the designer-focused development paradigm.

Recent innovators, Curl Corporation and others, have addressed outstanding development issues by providing an application development platform for the Web--enabling the delivery desktop-like applications in the browser. These new solutions are based their own scripting languages, development tools and methodologies, that facilitate Web application development. To their credit, these companies have recognized the need for a true Web application development environment; unfortunately, they have either retained the high cost of plug-ins and/or failed to adopt current Web standards.

The bottom line is that there are significant drawbacks to consider when it comes to applets and plug-ins. Overall, plug-ins pose significant integration, maintenance and security issues and intrude on other applications (attaching to the OS). And the most intrusive aspect of an applet or plug-in, it simply adds more "stuff' to the end-user's machine, as much as 15 MB. As a result, the market is looking for a better Web services solution--something that streamlines Web application consumption without the overhead of plug-ins.

Rich-Thin Client: Moving 10 the Executable Internet

Rich-thin clients capitalize on the standard capabilities that exist within the browser--delivering on the promise of an executable Web. The evolution of Web technologies is now enabling fully functional Web applications to execute within the browser, using technologies native to the browser. Rich-thin client solutions build upon standard HTML by including object-oriented, visual and nonvisual components delivered as JavaScript classes. These JavaScript components turn an HTML Web page into a rich Web application that looks and acts like a familiar desktop application with buttons, grids, dialogs, wizards, data communication, data translation, etc.

Rich-thin client solutions build upon industry standards and protocols utilized by reading browsers. The keystone of this architecture is the W3C Document Object Model (DOM) that reduces a Web page down to its most basic elements, allowing it to be reorganized or manipulated using JavaScript. The foundation of a rich-thin client solution is the Browser Application Platform a collection of JavaScript components that creates, manages and maintains these fundamental DOM elements when executing a Web application.

Unlike plug-ins, the rich-thin client's Browser Application Platform is significantly smaller, is downloaded at execution time and is cached in the browser. Web applications developed using a Browser Application Platform can be delivered seamlessly to end users, without the need for installing any components on the client machine.

The development paradigm for rich-thin client applications has existed in the client/server world for well over a decade and leverages the simplicity and ease of development familiar to most developers today. Instead of relying on a graphic artist or Web designer, developers can define the visual appearance and server interaction of the application as XML and can then customize the application using JavaScript.

Successful rich-thin client solutions provide sophisticated features that include data communications that ensure standards support at both an application and protocol level: HTTP, HTTPS, SOAP, UDDI, etc. These features allow even an entry-level developer to easily create meaningful applications that communicate with multiple and disparate sewer architectures and easily connect with existing Web Services.

In general, this type of Web Services delivery method offers better performing and more powerful cross-platform Web applications; helps to reduce enterprise development, deployment, and maintenance costs; and provides a much more effective use of existing server and bandwidth capacity.

Rich-thin client Web applications also integrate seamlessly into almost any enterprise network. By delivering high levels of interoperability, this innovative technology supports, rather than replaces, existing corporate investment in IT, legacy systems, client/server systems, etc. In short, rich-thin client Web applications specialize in helping any enterprise put fully functional user interfaces on their complex business systems.

Considering All of the Options

Choosing the right Web Services delivery method is a paramount decision for all IT professionals. It can affect both the technological vision of a company and future financial successes. Under the Web's current architecture, HTML alone is incapable of delivering usable Web applications or directly accessing a Web Service.

Applets, plugins and rich-thin client delivery offer better performing and more powerful Web - based applications than current HTML Web forms. However, there are some significant drawbacks with applets and plug-ins. Remember, applets and plug-ins pose integration and security issues, are hard to install and maintain and intrude on other applications (attaching to the OS).

Rich-thin client solutions eliminate the deployment/upgrade nightmare and offer the most technically friendly option available--clearly delivering the most effective and efficient Web application computing environment and Web Services delivery method.

Bruce Grant is chief architectural officer, Dave Mitchell is senior engineer and system analyst, and Scott Lemon is chief strategy officer at Vultus (Lindon, UT)

www.valtus.com