Linux may be a free platform for many and a reasonably inexpensive alternative to Unix and proprietary platforms for others, but make no mistake. For years, Linux has been big business, and if projections made by the market researchers at IDC turn out to be correct, in a few short years the Linux server ecosystem spending on hardware, software, and services directly relating to the platform will hit $49 billion by 2011. That's more than twice the $21 billion in Linux-related server spending that IDC reckons the companies of the world accounted for in 2007.