Charles Redding needed a better way to deploy a suite of 43 line-of-business applications to his rapidly growing list of remote offices. Redding is CIO at Masco Contractor Services that provides contractor installation services to businesses and consumers. With 11,000 employees in 260 field locations and acquisitions that have kept the company growing at a 25 per cent annual rate, he decided to centralise and provide virtualised access to those applications by way of Citrix' thin client, MetaFrame Presentation Server.

Now when a new store comes on-line, Masco can immediately provide secure access in an encrypted session for any client with a Web browser and a network or Internet connection. "We go back and standardise equipment, but from Day 1 that's not a mandatory thing," Redding says.

Providing branch office access to key line-of-business applications is just one use of thin-client computing serverware, also known as server-based computing or virtual user interface software. Virtualisation makes the management of desktops easier by moving applications to a back-end server. Low overhead requirements on the client allow IT to delay PC upgrades or move to Windows terminals.

Virtualisation also improves security by keeping data centralised - only screen updates and keystroke information pass between the thin client and server. The systems have also added support for authenticated remote access and Secure Sockets Layer (SSL) encryption so users can securely access applications via the Web.

Those features have stoked renewed interest in thin-client technology as a way to solve specific problems. Yet most companies that use thin-client serverware deploy it across only a portion of all desktops and use it only to access a select group of applications.

About 90 per cent of US Fortune 1,000 companies have deployed applications using technologies such as MetaFrame or Microsoft's Terminal Server, but most have installed it on only 10 to 15 per cent of desktops, says David Friedlander, an analyst at Forrester Research. That trend is unlikely to change soon, say users and analysts.

Limiting Factors
It seems that users and administrators are still more comfortable with a fat client. Americo Life, which has virtualised nearly all of its 50 applications on 32 MetaFrame servers, still gives its 550 users a full PC. "It gives me the flexibility to still run applications locally if I ever should need to do so," says CIO Randy James. But, Friedlander points out, "that means the PC still needs to be managed and patched."

Meanwhile, improvements in software deployment and desktop management tools have lowered the costs of managing traditional Windows desktops, reducing the relative benefits of thin-client systems in this area.

Power users still aren't a good fit for thin clients. Even with today's fast servers, resource-hungry applications such as computer-aided design systems still work better on stand-alone machines. For some mobile users, the need for a continuous network connection has limited the technology's appeal. And older applications can suffer compatibility problems because the application must be hosted on a Windows server running MetaFrame or other thin-client serverware. "We've had some problems, and most of it was specialised legacy stuff, applications running off Cobol," says Redding.

The evolution of the Web has given users another thin-client alternative. As companies move toward Web-enabling internal applications and enterprise software vendors increasingly provide Web-enabled software, users can access line-of-business applications by way of Web portals and SSL VPNs.

Thinning Ranks
Citrix's MetaFrame has long been the leader in thin-client serverware, and after a wave of consolidations in the past two years, administrators have fewer alternatives. Citrix holds about 75 per cent of the market, with the rest split among Microsoft, Tarantella, and a few others.

Sales of the technology actually dipped in 2002, but interest has picked up again. Citrix has broadened its offerings and positioned its products as a way to provide a single point of access to a mix of application types. Its Access Suite includes an SSL VPN product, single sign-on software and a conferencing tool. But the bulk of Citrix's business remains with MetaFrame Presentation Server, which it promotes as an easy way to Web-enable applications without rewriting them.

Microsoft has added features to Terminal Server such as improved scalability, and a faster version of the Remote Desktop Protocol client that make it an attractive - and less expensive - alternative to MetaFrame. But Citrix still leads the pack with the most enterprise-class features, including scalability, load balancing and fault tolerance.

"It's improved to the point where you can have data centres in different regions publishing the same applications and failing over to each other seamlessly," says Marc Mangus, national director of technology at systems integrator Vector ESP.

That was a critical feature for Scotiabank, which put 20,000 users and 1,000 bank branches on a MetaFrame server farm last July. It has two 50-server sites to provide fail-over support for 35 branch office applications, says J.P. Savage, the bank's senior vice president of systems.

Somerfield Stores got around the problem of how to host older applications by choosing a product that doesn't require them to reside on the same system as the serverware. Rather than host applications directly, a Secure Global Desktop server from Tarantella acts as a middleware layer, presenting a virtual user interface to the end user while communicating to the back-end servers using each system's native protocol.

The grocery chain used Tarantella's product to bring antiquated database applications running in some 600 stores into the data centre. That improved performance while giving Somerfield time to design a new database, says John Pelling, head of IT services. The new system paid for itself in 13 months by allowing the company to defer the costs of buying and deploying store hardware and software upgrades, he says.

The most common reason IT managers cite for using thin-client serverware is to save the time and expense of maintaining and replacing PCs distributed across multiple locations. "We can deploy a new application to 500 users in an hour," says Americo's James.

But Pelling and other IT managers also say they want to Web-enable all of their applications. As applications become more Web-centric, people are likely to move to portal software, says IDC analyst Dan Kusnetsky, although most companies have hundreds or thousands of applications, most of which are unlikely to be rewritten anytime soon.

Thin-client serverware is unlikely to broadly replace fat PCs, Kusnetsky adds, but it will continue to play a role in managing desktop access for specific applications.

James says he thinks companies are missing out by not deploying the technology more widely. He says centralising desktop applications and data has made it much easier to comply with the Sarbanes-Oxley Act and has reduced desktop administration problems to the point where his staff spends 60 per cent of its time on new projects. "For the typical IT shop, 90 per cent of their time would be consumed just keeping the place running," he says. "I don't know why more people don't do it."