Impedence mismatch is not a Microsoft term. It is a general term applied to the problems of matching relational data to OOP. It's a very difficult problem to solve. Entity Framework is one possible solution.

http://blogs.tedneward.com/2006/06/26/The+Vietnam+Of+Computer+Science.aspx

Ted's followup post is just as interesting. Note particularly point #8

http://blogs.tedneward.com/2006/06/27/Thoughts+On+Vietnam+Commentary.aspx


>Hi Mike,
>
>indeed. If you read the MSDN overview on the Entity Framework, it talks about solving the "impedance mismatch" (their term) between data and objects. And the MVC framework is yet another attempt at the same thing. Just as Linq was. Just as ADO.Net was. VFP has no impedance mismatch, of course.
>
>In Net 4.0, they have a new static type called Dynamic. So they can declare a variable dynamic and then create an object using the, e.g., IronPython compiler, as we would use newobject(). So dynamic languages within Net 4.0 can run, but they are second-class citizens, held at a distance.
>
>The eTecnologia VFP Compiler for .Net effort, however, produces first-class .Net dll's, CLI-compliant, that can be called just as though they were written in any of the static .Net languages.
>
>So, once again, VFP was there first. <s>
>
>Hank
>
>>I found this interesting comment by Beth Massi as she discusses the history of Visual Studio in her most recent blog entry:
>>
>>"I came from a different background (dbase), and not a Microsoft product until 1990 (they bought FoxPro). Always a data-based programmer I didn’t have much experience with C++ back then, and only a tiny bit of Visual Basic. (Why would I, VFP had LINQ and OOP in 1995 ;-))"
>>
>>Who knew at that time that VFP was foreshadowing things to come over 10 years later. Oh wait, if I'm not mistaken, C# 4.0 is going to be a "dynamic language" too. I'm not sure what that means, but somehow I get the feeling VFP was there already.
>>
>>What's old is new again.