Mac OS X is making inroads into the US business community, according to a Jupiter Media report.

The report found that in businesses with 250 employees or more, 17 per cent of the employees were running Mac OS X on their desktop computer at work. In businesses that had 10,000 or more employees, 21 per cent of employees used Mac OS X on their desktop work computer.

Mac OS X Server is also gaining ground. Nine per cent of companies with 250 employees or more used Mac OS X Server, while 14 per cent of companies with 10,000 employees or more used Apple's Server software.

Jupiter Media senior analyst Joe Wilcox observed: "What we are seeing is Mac OS X taking share aware from traditional Unix installations," he said, adding, "in some cases, OS X is taking share away from Windows, as well."

Wilcox explained that large businesses with expensive Unix systems are opting for Mac OS X when they upgrade for a variety of reasons. OS X is winning out over Linux in some cases as well, said Wilcox because these businesses would already have Unix expertise on staff; OS X has a good stable of server applications and it can run traditional Unix applications too.

Jupiter also sees opportunities for Apple with companies that currently run a Unix and Windows combination. With Mac OS X's Unix underpinnings, companies can use Apple's operating system to replace the other two.

Microsoft's Windows operating system saw a marginal decrease in installed base this year, according to the report.

Wilcox said it was too early to gauge reaction to Apple's recent announcement that it intends to switch to Intel-based systems next year. While cost will be definitely be a factor, Jupiter's Wilcox said that hardware is not always the most costly element to a major switch.

"With a lot of these systems the biggest cost is software, not hardware," he said.

Linux users also represent a big pool of potential switchers, according to the report.

"I'm surprised to see just how much Mac OS X has captured the interest of potential Linux switchers," said Wilcox. "Companies that were considering Linux are now buying Mac OS X instead."