Microsoft SharePoint 2010 introduces several new architecture changes including being 64-bit only and using a Service Application (SA) model instead of the Shared Service Provider model. The new SA model connects various services like Business Connectivity Services, Excel Services, and User Profiles to web applications through SA proxies. SharePoint 2010 also features enhanced sites, content, communities, search, and business intelligence capabilities. Key features include the new ribbon UI, managed metadata, audio/video support, social tagging, enterprise wikis, refined search, charting, and an integrated Project Server 2010 service application.