"Microsoft Windows is emerging as an acceptable operating system for high-performance computing (HPC) clusters in place of Linux, lowering the bar for entry into that space, according to some analysts and major vendors.
"In 2006, Microsoft announced the release of Windows Compute Cluster Server (CCS) 2003, marking the company's first attempt at an operating system for HPC applications. Industry observers say that Windows CCS has been well accepted, particularly for small computing clusters..."
