<p>I have heard that LINQ2SQL has been written to support multiple database vendor providers however for internal political reasons at MS, only SQL Server has been supported.</p>

<p>Is this a fair summary of the situation, and if so has a timetable been released as to when other databases will be supported?</p>

<p>I am aware of Matt Warren's <a href="http://blogs.msdn.com/mattwar/archive/2007/07/30/linq-building-an-iqueryable-provider-part-i.aspx" rel="nofollow noreferrer">BUILDING AN IQUERYABLE PROVIDER</a> series on the wayward weblog, but I would prefer not to build something now that will be released (probably better than I will do it) later</p>

Check the
ADO.NET Entity Framework
(and
Linq to Entities
), you can look here also a
Sample Entity Framework Provider for Oracle
, and
here
are more examples about creating Data Providers for EF.