I would like to start the new category for search related topics in SDN with pointing you to a whitepaper that covers interoperability of SAP NetWeaver Enterprise Search based on the OpenSearch standard. 

SAP NetWeaver Enterprise Search is SAP's new productized search solution that entered Unristricted Shipment as of December 23, 2008. See SAP NetWeaver Enterprise Search has entered Unrestricted Shipment.

Together with my colleagues Pedro Arrontes and Holger Bruchelt I recently published the whitepaper Federated Search between SAP NetWeaver Enterprise Search and Microsoft Search Server 2008.

This topic has been presented by me at SAP TechEd this year in the Hands-On Session 
UP265 - Interoperability Between SAP NetWeaver Enterprise Search and Microsoft Enterprise Search.

In addition to the content presented at SAP TechEd we could now show that it also possible to achieve Single-Sign On based on Integrated Windows Authentication in this scenario.

Best regards,
André