Entity Framework (EF) v1 is the first and — when this book was written — the only concrete implementation of the Entity Data Model (EDM). EF's owner is Microsoft's SQL Server Data Programmability (DP) group, which is responsible for the entire ADO.NET technology stack, including ADO.NET Data Services, ADO.NET Synchronization Services, and SQL Server Data Services. EF competes directly with LINQ to SQL, which was developed primarily by members of the ObjectSpaces team, initially Matt Warren and Luca Bolognese of the C# group.
Matt Warren's The Origin of LINQ to SQL blog post of May 31, 2007 (
http://blogs.msdn.com/mattwar/archive/2007/05/31/the-origin-of-linq-to-sql.aspx) recounts the demise of ObjectSpaces in the black hole of WinFS and describes his three years after the event as a "political nightmare."
DP gained control of the LINQ to SQL implementation in October 2007, shortly before VS 2008 released to manufacturing. The DP group positions LINQ to SQL, which shipped with the original VS 2008 release, as a rapid application development (RAD) O/RM tool for small to medium-sized business applications. DP product managers claim EF is an enterprise-grade product that's capable of mapping complex object constructs, such ...