This is the stand-alone Object Model Installer for TFS 2010 (Sp1). This may be used for developing applications that integrate with TFS 2010.
This is the same Object Model included with the Visual Studio & Team Explorer SKU, in a stand-alone package. This OM will allow applications to connect to a TFS 2010 server, without the need for a Visual Studio or Team Explorer being installed on the machine. (Proper licenscing / CALs are still required)