Windows 7 introduces support for search federation to remote data stores using OpenSearch technologies. Federated search enables users to search remote data sources from within Windows Explorer and to interact with that remote data from within Windows Explorer.
This document describes how to build a web-based data source that can be searched using Windows federated search. Following the best practices described here, you can enable rich integration of your remote data sources with Windows Explorer without having to write or deploy Windows client-side code.
Windows 7 federated search supports the following standards:
For item data:

• RSS 2.0, 1.0, 0.91 & 0.92
• Atom 0.3 & 1.0
• MediaRSS content and thumbnail elements

For connection information:

• OpenSearch 1.1

Authentication:

• NTLM
• Kerberos
• Basic (only over https)
• plus any other Security Support Providers installed on the client and the server hosting the web service

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