The Platform Update for Windows Vista is a set runtime libraries that makes it easy for developers to target both Windows 7 and Windows Vista.
Among the technologies included in the Platform Update for Windows Vista are the XPS Print API for XPS Printing, the XPS Rasterization Service for XPSDrv-based driver development, and the XPS Document API + Packaging API for the creation, manipulation and access of XPS content. This enables developers to take advantage of new Windows 7 APIs to access existing features while ensuring their applications will work on Windows Vista SP2 and Windows Server 2008 SP2, and underscores our commitment to ISVs and IHVs that are developing solutions to take advantage of the XPS format.
For more information on Windows 7 Graphics Update for Windows Vista see http://blogs.msdn.com/directx/.
The XPS Print API is included in the Platform Update for Windows Vista. This allows Win32 developers to send XPS content directly to the XPS Print Path. It also supports automatic conversion to support non XPS printing devices. The XPS Print API is detailed on MSDN at this link: http://msdn.microsoft.com/en-us/library/dd374565(VS.85).aspx .
The XPS Rasterization Service provides an inbox solution to XPSDrv driver developers who require rasterized content. The driver developer can write a print filter pipeline filter that calls the service, which will return rasterized content. This service is introduced in Windows 7 and is now available through the Platform Update for Windows Vista to Windows Vista SP2 and Windows Server 2008 SP2. Information on the XPS Rasterization Service can be found at http://msdn.microsoft.com/en-us/library/dd445665.aspx.
The XPS Document API and Packaging API support the functionality required to work with the XPS Print API and XPS Rasterization Service, these components may be used to work directly with XPS content, although some API features available in Windows 7 and Server 2008 R2 are not available in the Platform Update for Windows Vista. These differences are detailed below.
XPS Document API provides interfaces to work directly with XPS Documents. In the Platform Update for Windows Vista, XPS Document API implements all the Windows 7 interfaces except for digital signature functionality (see XPS Document API link in the MSDN link: http://msdn.microsoft.com/en-us/library/dd316975(VS.85).aspx.
The Packaging API in the Transition Pack will only expose the following interfaces needed by the XPS Document API.
o All Win7 interface methods are supported
o Supported interface methods
The Windows 7 documentation for Packaging API can be found here: http://msdn.microsoft.com/en-us/library/dd742822(VS.85).aspx. Note that this link discusses all of the Packaging API functionality, not just the interfaces included in the Transition Pack listed above.
The Platform Update for Windows Vista will be released to the public in the fourth quarter of 2009. A public beta will is available on 9/10 (see http://windowsteamblog.com for details on how to get the beta).