Entity Framework originates from WinFS
As I started to learn more about Entity Framework, i stumbled upon an interview with Quentin Clark who led the WinFS project from 2002 to 2006. WinFS was shut down in 2006 but much of the work done their lives today in several area's as QC mentions
"Now let's look under the covers, and ask what was required to deliver on that goal. It's about schemas, it's about integrated storage, it's about object/relational, a bunch of things. And that's the layer you can look at and say, OK, the WinFS project, which went from ... well, it depends who you ask, but I think it went from 2002 until we shut it down in 2006 ... what was the technology that was being built for that effort, in order to meet those goals? And what happened to all that stuff?
You can catalog that stuff, and look at work that we're doing now for SQL Server 2008, or ADO.NET, or VS 2008 SP1, and trace its lineage back to WinFS."
Read the full interview here: http://perspectives.on10.net/blogs/jonudell/Where-is-WinFS-now/
Additionally I learned a lot from Craig Stuntz post and Danny Simmons post about the purpose of EF and comparison between other ORM's.