"Of course, as noted, there remains plenty of revenue growth in Linux, as IDC notes, though most of it is still not coming at Microsoft's expense:
"Linux is set to outpace the larger market, with customer spending on Linux expected to grow year over year by 21 percent in 2009. The larger software market, meanwhile, will struggle to deliver 2 percent growth in 2009. And from 2008 to 2013, the Linux market is set to grow $12.3 billion to $35.5 billion, representing a 23.6 percent compound annual growth rate.
"Even so, it is important to note that the size of Linux versus, for example, Windows, is telling: the Microsoft software ecosystem was $149 billion in 2008. IDC rightly points out that "even with a sub-10 percent growth rate through 2013, (the Microsoft ecosystem) will add $56 billion in spending."
