IBM's chief information officer has directed the company to begin an internal project to evaluate Linux for use on desktop computers, in a further endorsement of the open-source operating system.

A November memo from CIO Bob Greenberg said IBM chairman Sam Palmisano has "challenged the IT organisation, and indeed all of IBM, to move to a Linux-based desktop before the end of 2005." IBM's actual plan, however, is not so bold, spokeswoman Trink Guarino said Thursday.

"IBM has no plans to move all of its employees to Linux desktops by 2005," or even a majority of them, she said. Instead, IBM has begun a project to seriously evaluate Linux for use on desktop computers, which is a domain where Microsoft is most powerful.

Big Blue long has advocated use of the open-source operating system on servers -- powerful networked computers often run by trained system administrators -- but only in late 2003 began warming to desktop Linux.

IBM's actions, however tentative, can be influential. Its endorsement of Linux on the server in 2000 went a long way to establishing the credibility of the comparatively new operating system with its humble origins as a student programming project.

Guarino likened the desktop Linux effort project as similar to the evaluation of server Linux that began well before the company officially endorsed the idea in 2000. "It's routine for IBM to challenge its internal IT teams to rigorously test new platforms and technologies inside IBM," she said.

It's clear, however, that IBM is taking desktop Linux seriously. Greenberg's office is leading the Open Desktop project. With participation from IBM's research and software groups, the project will work on "replacing productivity, Web access and viewing tools with open standards-based equivalents," the memo said.

Desktop Linux has held promise for years but hasn't caught on widely, hampered by technical challenges, software availability and compatibility issues. The market is moving faster now, however, with new interest from government customers such as the cities of Munich, Germany, and Austin, Texas, and major product initiatives from companies such as Sun Microsystems.

The two dominant Linux sellers, Red Hat and SuSE Linux, also have desktop Linux projects and products, while a host of start-ups are angling for the market. For example, on Wednesday, Linux PC maker Linare announced that Walmart.com is selling its $200 (£109.36) Linux-based PCs.