SharePoint 2010 Software Development Kit is now available
The final Version of the Microsoft SharePoint 2010 Software Development Kit is now available as a free Download from the Microsoft Download Center.
The Microsoft SharePoint 2010 Software Development Kit (SDK) includes documentation and code samples for Microsoft SharePoint Foundation 2010 and for Microsoft SharePoint Server 2010, which builds upon the SharePoint Foundation 2010 infrastructure.
Visit the following Microsoft Website to download the SharePoint 2010 SDK:
Microsoft SharePoint 2010 Software Development Kit
The Microsoft SharePoint 2010 Software Development Kit contains conceptual overviews, programming tasks, samples, and references to guide you in developing solutions based on SharePoint 2010 products and technologies.
Download -> SharePointPlatformSDK.exe
The documentation includes detailed descriptions of the technologies that SharePoint Server 2010 and Foundation 2010 provide for developers, reference documentation for the server and client object models, and step-by-step procedures for using these technologies and object models and programming with them. This SDK also includes best practices and setup guidance to help you get started with your own custom applications that build and extend upon the SharePoint Server 2010 and Foundation 2010 platforms.
For additional information, you can visit the SharePoint Developer Center on the Microsoft Developer Network: http://msdn.microsoft.com/sharepoint.