This new feature is an extension to Visual Studio for modeling LINQ to SharePoint entities directly in VS2010. With this tool, it’s become possible to add a new kind of item in a VS project, that we name a LINQ to SharePoint schema.
LINQ to SharePoint DSL project contains the following features:
Visual Studio 2010 Extension to manage *.l2sp schema files and generate code
New "SharePoint Data Model" Visual Studio item type
Wizard to build a mapping model
Preconstructed SharePoint site models including blank model, team site, publishing site, enterprise wiki, blog, document workspace, ...
Wizard to automatically load the model from an existing SharePoint 2010 web site
Visual LINQ to SharePoint entities designer
Automatic generation of code thanks T4 text templating technology