Background

Federated Search has been introduced with Microsoft Search Server 2008 (MSS 2008). It allows MSS 2008 to pass search requests to other search providers (Google News, Live.com, Yahoo News, etc) and display the results in one place. Basically, to implement a federated search in MSS 2008, you download a Federated Search Connector file, .FLD. FLD stands for Federated Location Description. This file is based on the Open Search standard and is uploaded to MSS 2008 to enable the federation.

More info here: http://www.microsoft.com/enterprisesearch/connectors/federated.aspx

MOSS 2007 & Federated Search

MOSS 2007 does not currently support federated search as this was introduced with MSS 2008. However, I did find the following post that states an update to MOSS 2007 will be made available when MSS 2008 RTM is released that will add the Federated Search capabilities.

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2482165&SiteID=1