At Mix 07, the ADO.NET team announced an incubation project that they have been working on, Project Codename "Astoria".
What’s this “Astoria” now ! – hold on lets look at the goals and high level features
The goal of Microsoft Codename "Astoria" is to enable applications to expose data as a data service that can be consumed by web clients within a corporate network and across the internet.
The data service is reachable over HTTP, and URIs are used to identify the various pieces of information available through the service.
Interactions with the data service happens in terms of HTTP verbs such as GET, POST, PUT and DELETE, and the data exchanged in those interactions is represented in simple formats such as XML and JSON.
The first early release of Astoria will be a Community Tech Preview that you can download, as well as an experimental online service you can access over the internet.
Check out the Astoria webpage at http://astoria.mslivelabs.com for more information and a link to the download.