Windows XP is not supported by DirectX 10.0 and above. Unlike prior versions of the API, Direct3D 10 no longer uses "capability bits" (or "caps") to indicate which features are supported on a given graphics device. Instead, it defines a minimum standard of hardware capabilities which must be supported for a display system to be "Direct3D 10 compatible". This is a significant departure, with the goal of streamlining application code by removing capability-checking code and special cases based on the presence or absence of specific capabilities. Because Direct3D 10 hardware was comparatively rare after the initial release of Windows Vista and because of the massive installed base of non-Direct3D 10 compatible graphics cards, the first Direct3D 10-compatible games still provide Direct3D 9 render paths. Examples of such titles are games originally written for Direct3D 9 and ported to Direct3D 10 after their release, such as "Company of Heroes", or games originally developed for Direct3D 9 with a Direct3D 10 path retrofitted later in development, such as "" or "Crysis". The DirectX 10 SDK became available in February 2007. Direct3D 10.0 level hardware must support the following features: The ability to process entire primitives in the new geometry-shader stage, the ability to output pipeline-generated vertex data to memory using the stream-output stage, multisampled alpha-to-coverage support, readback of a depth/stencil surface or a multisampled resource once it is no longer bound as a render target, full HLSL integration – all Direct3D 10 shaders are written in HLSL and implemented with the common-shader core, integer and bitwise shader operations, organization of pipeline state into 5 immutable state objects, organization of shader constants into constant buffers, increased number of render targets, textures, and samplers, no shader length limit, new resource types and resource formats, layered runtime/API layers, option to perform per-primitive material swapping and setup using a geometry shader, increased generalization of resource access using a view, removed legacy hardware capability bits(caps). Direct3D 10.1 was announced by Microsoft shortly after the release of Direct3D 10 as a minor update. The specification was finalized with the release of November 2007 DirectX SDK and the runtime was shipped with the Windows Vista SP1, which is available since mid-March 2008. Direct3D 10.1 sets a few more image quality standards for graphics vendors, and gives developers more control over image quality.