In addition to Office Professional 2010, the Office365 Beta includes an updated communication and collaboration suite known as Microsoft Online Services. It consists of the cloud-based versions of Exchange 2010, Lync Server 2010, and SharePoint 2010.
The process of building solutions for SharePoint Online is similar to SharePoint 2010. Developers can use the same tools they’re accustomed to, such as SharePoint Designer 2010, Visual Studio, and the SharePoint API and SDKs. However, there are several key differences that must be taken into account when planning to deploy a SharePoint solution on Office365 Beta.
For example, Farm scope (for an entire server farm) is not available on SharePoint Online, as it runs in a shared datacenter with multiple clients. Only Site and Web scopes apply in the cloud. Full Trust is not available for the same reason.
While a majority of SharePoint 2010’s features are also available for SharePoint Online, some are not supported. (The Office365 documentation provides a full side-by-side comparison of the two platforms.) Business Connectivity Services are not currently included, but there are plans to add them at a later date. One of the more interesting exclusions from SharePoint Online is Web Services, because their use is not supported in only partial-trust applications. Microsoft does note, however:
“Although … external data connections are not available for use in sandboxed solutions, you can access them through client applications such as Microsoft Silverlight and ECMAScript (JavaScript, JScript).”
Because of the limitations of using SharePoint Online in the cloud, Microsoft recommends developing for it using Sandbox Solutions, so that applications will automatically meet the criteria for scope and trust.
Sandboxed SharePoint solutions in Visual Studio 2010 support IntelliSense, but do not include compilation support. To aid with this, Microsoft recently introduced Visual Studio 2010 SharePoint Power Tools, which add compilation support and a Visual Web Part project item template specifically tailored to sandboxed SharePoint Online projects.The SharePoint Online developer guide is available now from the Microsoft Download Center.