Creo que este es un artículo de lectura casi obligatoria (en inglés). Escrito por Andrew Connel (MVP de MOSS). Transcribo:
In SharePoint 2010, you'll notice an area that was given great attention. It's now easier to work with SharePoint data in multiple scenarios. In SharePoint Foundation 2010 (SPF2010), Microsoft added LINQ support to help you create solutions that run on SharePoint servers. By introducing a RESTful service that exposes all lists and their contents, Microsoft also addressed the challenge of working with SharePoint data coming from external applications. Thankfully, Microsoft didn't stop there.
With every release of SharePoint, customers consistently requested new Web services. The latest release of SharePoint contains a vastly reworked user interface (UI) that dramatically reduces the number of page refreshes. Microsoft needed something new to satisfy its own demands for the improved UI and to provide a better and more robust platform for creating solutions that will run off SharePoint servers. This has been achieved with the client object model, which consists of three major components (.NET, Silverlight, and ECMAScript) that you can use in various situations.
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