Microsoft Lync 2010 SDK includes:
Managed Microsoft.Lync.Model.dll assembly that expose the types used in your project.
Microsoft Lync Controls.
Microsoft Lync 2010 API.
Microsoft Lync 2010 Framework programmers guide.
Sample application projects.
Lync SDK is installed locally using LyncSdkSetup.exe.
Lync 2010 Framework should be used by application developers who intend to build custom Microsoft Lync 2010 applications or embed collaboration functionality in line of business (LOB) applications that interoperate with other custom Lync SDK clients or Lync 2010 and Microsoft Lync Server 2010. With Lync 2010 Framework, a developer can provide instant messaging (IM), voice, video, application sharing, and meeting session functionality within a custom client or LOB application.
Lync 2010 Framework is a client API that combines the automation capabilities of Microsoft Office Communicator 2007 Automation API with the functionality of Microsoft Unified Communications Client API. To access Lync 2010 API features in an application you produce with Lync SDK, you must launch a Lync 2010 client on the local host computer.