LINQ to SQL, LINQ to Amazon, LINQ to Coffee Machine ...
At "Meet the LINQ Team" session at TechEd, I got a few questions about LINQ to SQL and if it was possible to build a similar implementation. The answer is - absolutely you can. Take the soon-to-be released expression tree API documents, a few samples on the net and start cooking. What can you build a LINQ provider for? Any source of data worth querying. Who knows, it could be a smart fridge which tells you about the contents and perhaps down the road - your coffee machine.
The complexity of a provider depends on:
1. What set of query operators you choose to implement; and
2. Difference between the query operators and the target query language or API; and
3. Level of optimization or tuning you want to do; and finally
4. Availability of samples (yes, you guessed right. Our team members are working on this one in addition to the community at large)
Coffee machine aside, there are many providers already available. Most are based on May 2006 LINQ CTP but most can be upgraded to .NET Framework 3.5 without too much effort. Charlie's blog post and Oakleaf systems blog post have good starter lists.
I am a program manager in the Visual C# Product Unit of Microsoft. I am currently working on the LINQ project with specific responsibility for DLinq. Previously, I have been in a PM in SQL Server working on ObjectSpaces and DataSet.
In pre-MS life, I have worked for companies ranging from startup to IBM on a wide range of software projects.
Before I started working, I did M.S.E.E. and Ph.D. (CSE) from the University of Notre Dame and B.Tech. E.E. from IIT Bombay, India.