Microsoft Windows servers showed positive growth as revenues grew 9.4% and unit shipments grew 5.1% YTY. Significantly, quarterly revenue of $5.3 bln for Windows servers represented 34.9% of overall quarterly factory revenue, the single largest revenue segment in the server market. Unix servers experienced 2.8% revenue growth YTY when compared with Q4 2006. Worldwide Unix revenues were $5.1 bln for the quarter, representing 33.5% of quarterly server spending and reflecting continued IT investment in this server market segment, with particular strength in the high-end enterprise segment of the Unix market. Z/OS experienced its third consecutive quarter of positive revenue growth growing 5% YTY in Q4 2006 to $1.7 bln. This is the highest quarterly revenue for IBM’s System z in 8 years. Z/OS accounted for 11.2% of all server revenue in Q4 2006.