We often rely on domain specific search (in music players, mail clients, photo clients) but with Windows Vista and Windows 7 we make it possible to search within a namespace and across namespaces. Federated Search enables you to search a remote web service from Windows explorer and get results back that you can act on like any normal file. Most of these content stores are already indexed on the server, or at least on some server. There are several great offerings that will accomplish this, such as Microsoft Search Server. Not only do these servers index this content, but many of them already expose search results via a standard web protocol. This is largely thanks to the prevalence of OpenSearch and RSS enabled clients (including Internet Explorer and Microsoft Search Server, among many others). For Windows 7, we’ve added support for Federated Search using OpenSearch v1.1 and worked to make the experience a seamless one.