The concept of network computers is simple: why put on every desk an expensive personal computer that requires constant upgrading and lots of management? Why not put all your programs on to a giant computer or server and distribute software and files via a network? Any work files or data can be saved on the server too.
The result is a network computer (NC) that needs just a small amount of memory and no hard disk, making it relatively cheap (about a half to a third of the price of a PC), simple to use and easy to manage. In the parlance, PCs are "fat clients", which become bloated with programs and files and require more and more memory and bigger hard disks to do their job. Network computers, in contrast, are "thin clients" - lean, mean machines that require fewer resources and less management time.
Nick Evans, Xemplar's head of marketing, says the company is selling "quite a few" network computers, but adds: "The NC is not an easy buy because you're bucking the trend and doing something different. But issues such as cost of ownership and management are making the NC more appealing. It's also an open system - NCs are based on Internet technology, so you can run a mix of computers on the same network, say Macsand PCs."
Schools may also have been put off by the exaggerated claims made by some netwrok computer supporters. They will not make desktop computers obsolete. In some areas, such as multimedia and graphics work, they are still the best option. Many find that a mix of network and desktop computers works best.
St Sebastian's school in Wokingham has taken part in a project supported by Sun Microsystems, New Vision, Aironet and Datatech that has involved the installation of four network computers called Java Stations (named after the software created by Sun) and a computer for connecting to the Internet.
Mark Denne, local councillor and New Vision director, says: "If dedicated teachers find they have to give up valuable time to administer the school network, it seems to me that personal computers are the wrong type of technology to use in schools."
The headteacher, Jean Ashfield, says the school is pleased with its network computers: "They've enabled us to do so many things. For example, all our children have a mail box, and we have an email link with a school in Florida. The machines are easy to manage."
Sun has also provided 30 Java Stations to Linlithgow Academy in West Lothian. The school has a high-speed Ethernet network, with 350 access points.
Bob Ferguson, the Academy's deputy rector, says network computers might be the answer to the school's problems: "We want to provide enough facilities to make computer access across the curriculum a routine affair, but we can't afford to do this by buying lots more (desktop) computers.
"We also have some light-fingered pupils who tamper with their systems and that means spending time fixing the problems they cause. So security is also an issue. An NC is virtually tamper-free - everything is on the server."
Ferguson is conscious of the regular upgrading desktops require. "There's a lot of money around the system thanks to the National Grid for Learning, but the money won't last forever," he says. Linlithgow has a mix of Apple Macintosh systems and PCs; network computers will enable it to use all the machines on the same network.
Linlithgow plans to put network computers into a computer lab. "It's a big job training teachers how use technology, so we want to keep the NCs together in the initial stages. But later on we may put, say, 10 NCs in other parts of the school."
Ferguson admits that the jury is still out when it comes to using the network computer, but adds: "On the face of it, it looks like a good direction to go in."