Download SharePoint 15 Tech Preview SDK

SharePoint 15 Technical Preview Managed Object Model SDK contains reference topics focusing only on types and members that are called by other Microsoft applications. This reference does not document the full SharePoint 15 managed object model. That documentation will accompany a later release of SharePoint 15.

Download Link : http://www.microsoft.com/download/en/details.aspx?id=28768
Source : http://microsoftfeed.com/2012/download-sharepoint-15-tech-preview