As IBM has gotten deeper into the Linux fray, it has delicately balanced its promotion of both open source and Microsoft-based product offerings. Now Big Blue seems to be taking a more pro-Linux stance. As the company continues its campaign to push the replacement of Windows NT servers with Linux, it has launched an internal effort to install 40,000 Linux-based desktop PCs by year-end.Together with its reseller partners, IBM is aiming its external campaign at small and midsize businesses in a bid to encourage them to switch from Windows NT boxes to Linux servers. Dubbed the "NT-to-Linux Migration Program," IBM is looking to lure small businesses running Windows NT servers that are looking for an alternative upgrade when Microsoft ends support for NT at year-end.IBM says it has 45 active business partners in its migration program, and the vendor estimates that 50,000 Windows NT servers have been migrated to Linux so far this year. In addition to offering migration and support services for Linux, IBM business partners are also offering certified security applications for Linux servers, such as security software from Trend Micro and Check Point.Meanwhile, IBM's internal push to put Linux on more desktops is already underway. Big Blue says around 15,000 of its 300,000 employees use Linux desktops right now. IBM is using SuSE and Red Hat Linux desktops as part of this initiative.Part of this effort was spurred by a memo from IBM CIO Bob Greenberg that was made public earlier this year. Greenberg challenged management at the company to back a move to Linux desktops.But IBM is hedging its rhetoric a bit, saying recently that Windows-to-Linux migrations may not be for everyone. IBM had also created an Open Client Assessment program, originally aimed at moving customers from Windows to Linux PCs. The program has been restructured for server-based Windows-to-Linux migrations after IBM says it wasn't finding significant cost savings for customers with desktop migrations.