Sun's recent move to promote Linux use on its UltraSparc architecture for servers may be a strategic play to keep the vendor's hardware line selling, but it could also be a more tactical or short-term move for users looking to build an enterprise data center platform.Sun's OpenSparc initiative is aimed at making non-Sun operating system - i.e. Linux - rum more smoothly on Sun server hardware. The move mirrors similar efforts by IBM for its PowerPC hardware. But IBM has a several-year head start in pushing Linux on its RISC-based chip, and a not-insignificant customer base of Linux\/Power users. Fully-supported Linux on UltraSparc is still in its infancy.IBM and now Sun are taking advantage of Linux' popularity and the promise of lower software acquisition and maintenance costs over the legacy Unix systems that ran on their respective servers - AIX and Solaris. The idea is that the "free" in Linux and the perceived processing muscle behind the Power and UltraSpac brands will be the draw.But for many large enterprise users who have made the transition to Linux, the message is different - it's the hardware stupid. The commoditization, widely available support and improving performance of X86 hardware from Intel and AMD are the reasons many users jump into Linux. According to IDC, Intel and AMD servers grew by 18.2% year-over-year in the third quarter of 2005. However, mid-range enterprise servers, with Sun and IBM hardware falling into that category, declined 10.2%. Large-scale migrations from proprietary servers to Intel-based boxes was the main driver there, the analyst firm says.Opening up UltraSparc to Linux may be incredibly helpful for businesses looking to squeeze more life out of Sun hardware or integrate Sun servers into open source environments. How much mileage enterprise users might get out of such systems remains a question.