This package contains the complete Software Development Kit for Microsoft Dynamics CRM 2011.
Microsoft Dynamics CRM SDK Version 5.0.6 is now live on MSDN library and on the MSDN downloads.
Updated:
• Updated the Plug-in Registration Tool to work with Windows Azure AppFabric Access Control Services (ACS) 2.0. It is also backwards compatible with the previous version.
• Updated the Azure sample code readme files to explain the new setup procedures.
• See more updates in the Release History on the first page.

MSDN:
http://msdn.microsoft.com/en-us/library/gg309408.aspx
Download: http://www.microsoft.com/download/en/details.aspx?id=24004