And in the past year, the market share of Linux leapt from 6.8 percent to an estimated 17.2 percent of server operating system shipments, according to a study from International Data Corporation. The number of copies of Linux shipped to customers more than tripled from 1997 to 1998.
The massive growth spurt results from anti-Microsoft sentiment, strong performance, and low pricing, IDC analyst Dan Kusnetzky said. In addition, Linux can be narrowly tailored to users' needs, since sections of code can be modified or deleted as necessary, unlike other operating systems.
Linux, a relative newcomer to the operating system scene, was created by Linus Torvalds in 1991 when he was a computer science student in Finland. Since then, hundreds of independent programmers across the Internet have contributed to the development of the Unix-like software. This is possible because the Linux source code--the computer instructions in their original form--is freely available to anyone who cares to download or modify it.
Shipments of licenses for server operating systems increased 25 percent from 3.5 million in 1997 to an estimated 4.4 million in 1998. That means IDC counted about 236,000 Linux shipments in 1997 and 748,000 in 1998.
Although Linux's growth rate has been faster, Windows NT and Novell NetWare still have a greater market share, Kusnetzky said. In 1997 and 1998, Microsoft Windows NT Server accounted for about 36 percent of operating system shipments. NetWare has hovered at about a quarter of operating system shipments, with 26.4 percent in 1997 and 24.2 percent in 1998.
In recent years, Microsoft has been a growing presence in the operating system market, with Windows NT server shipments increasing 75 to 80 percent per annum, Kusnetzky said. IDC expects that growth soon to slow down to 20 to 30 percent range.
"NT shipments are growing quite nicely," he said. "Are they growing as fast as in the past? The answer is no."
Perversely, some of NT's growth is attributable to its weakness in handling multiple tasks. Because it doesn't "multitask" well, customers are buying multiple copies of NT and spreading functions over separate, discrete servers.
"A lack of scalability has forced Microsoft to push a functional server approach [in which a server handles a single task] rather than the multifunction server approach offered by Unix suppliers. This forces organizations to buy more copies of Windows NT than they would if they were assigning the mission to some other operating environment," Kusnetzky said.
Where Unix systems routinely handle email duties for 5,000 or 10,000 users, the biggest load IDC has seen on an NT machine is about 300 or 400 users, he said.
Unix shipments grew 4 percent from 1997 to 1998, well below the average. And in 1998, Linux shipments just about caught up to the rest of the Unix world.
Unix accounted for an estimated 17.4 percent of 1998 shipments, just a hair ahead of the 17.2 percent logged by Linux.
IDC has been tracking Linux since 1996, Kusnetzky said, monitoring shipments from companies that sell the operating system. The research firm doesn't track copies of the operating system downloaded off the Internet--where it can be obtained at no cost--because it's impossible to tell whether a download is actually installed on a server.