This is the second part of a two-part article. Part one was published last Friday.

Case studies

At Parsons, Visconti installed a streaming tool called AppExpress from Endeavors Technology two years ago. Now, he says, “I can get anybody up, anywhere in the world, on any application in five minutes. As soon as I have a patch, I patch it on the server, and in a few minutes, everybody has the new version.”

But AppExpress is not a conventional software-distribution tool. A Parsons engineer indicates via a Web portal which project he is going to work on, and a home-grown configuration management system instructs AppExpress to stream the needed applications to his desktop. It also streams configuration parameters related to printers, plotters and other devices.

“First, the server establishes whether the user has the application on his desktop,” Visconti says. “If not, it streams just enough so it starts to execute.”

While taking inventory of desktop contents, AppExpress can also find and report bootleg software, he says.

Visconti says Parsons may have saved as much as $1 million last year from the streaming technology, which served 600 PCs. “We are cutting the cost of IT support almost to nothing,” he says.

And Visconti says the “on-demand” nature of streaming — the user gets the application only when he needs it and for only as long as he needs it — has important software licensing benefits as well. He is striking enterprise agreements with software vendors that allow payment based on actual usage, which is determined at the end of each quarter. That kind of agreement enables Parsons to install all of a vendor’s products on AppExpress servers while paying for only the ones actually used, he says. And new applications get to users in minutes, not days.

Alternative approaches

The Cleveland Municipal School District takes a slightly different approach, using a pair of complementary products for software streaming. It uses the Software-Streaming Platform from Ardence (recently bought by Citrix Systems) to stream a standard “base layer” -- the operating system plus the core applications that all users need, such as Microsoft Office and Adobe Acrobat -- on each of 15,000 PCs in 104 buildings.

If a local machine becomes infected or corrupted in some way, it is simply rebooted using a new desktop image streamed from the data centre, and the user is back up in minutes. “The dream is to get all the desktops identical, then worry about layering applications on top of that,” says school district CIO Thomas Bender.

At the application layer, the school district uses AppStream from AppStream to provide applications that vary by user or user group, such as seventh grade maths students at a particular school. It taps into Active Directory for student profiles, and it can support software licence management by metering application use, Bender says.

Streaming has made it possible to centralise IT into one data centre rather than have servers distributed around the metropolitan area, Bender says. But, he adds, that would not have been practical without a network that features 1Gbit/sec fibre links to each school.

Russell Investment Group has a number of Windows XP desktops, which it calls “trim clients,” that receive applications published from Citrix Presentation Server. Although it will continue to use Citrix for remote access and delivery of client/server applications over its WAN, during the coming year Russell plans to migrate to Microsoft’s SoftGrid for delivery of applications to fat clients, says Greg Nelson, a senior technology consultant.

He says the need for access to rich media, such as video, has required compromise on a hybrid client computing model in which business applications are delivered via Citrix but rich content is redirected to the local desktop via SoftGrid. That will provide the benefits of server-based computing at a lower cost, with reduced complexity and increased flexibility, he says.

SoftGrid creates “encapsulated” virtual applications on a server and streams them to desktops as requested by authorised users. This encapsulation, or wrapper, has a number of benefits, Nelson says.

Application testing is easier because encapsulation eliminates DLL conflicts and permission problems. It also reduces the number of servers required for physical isolation of applications. Russell says he was able to reduce the number of Citrix servers by 50 per cent.

Migration to Windows Vista will be far easier than earlier upgrades were, Nelson says, because the applications are already abstracted from the local operating system.

Running applications on the desktop gives users better performance, Nelson says. The PCs Russell buys today have dual-core processors, 1GB to 2GB of memory, powerful video capabilities and cheap disks. With no server overhead or network latency, it just makes more sense to run applications locally, while still enjoying the benefits of centralised desktop maintenance that streaming offers, he says.

Nelson sums it up this way: “In a perfect world, I’d love to go all thin-client, but that’s not going to happen. What people want is rich content. People are becoming more mobile, and more richly connected.”

Culture shock

Streaming software to desktops has introduced "huge psychological change" at Parsons, says CIO Joe Visconti. "A lot of the IT support positions are gone. And just in time, because it's hard to find people who will do those jobs anymore," he says.

"And for end users, we found that a lot of them really like fiddling with their PCs, and it was up to us to educate their managers that this is not productive and they should stop that nonsense."

And users have gotten spoiled by the rapid response of IT to requests -- for new software, for example -- that is now possible. "Before, if it wasn't there in two weeks, all hell would break loose. Now if it's not there in five minutes, all hell breaks loose. It's like electricity -- it better be there."

Desktop streaming and virtualisation require a change in mindset on the part of IT support staff as well, says Greg Nelson of Russell Investment Group. Because virtualisation tools like SoftGrid insulate the application from the desktop environment, and because they can be easily restreamed from the server, traditional advice like, "Reboot your machine and call me if that doesn't help," is no longer appropriate in most cases, he says. And most visits to the desktop are not either, except in the case of hardware problems.

"The rules of rote that people grew up with are different now," he says. "You have to re-educate your support staff or you lose some of the efficiencies of these technologies."