Twitterizer

Twitterizer  is a .NET library designed for quick and easy Twitter integration.
http://www.twitterizer.net/

Linq to Entity framework

LINQ to Entities provides Language-Integrated Query (LINQ) support that enables developers to write queries against the Entity Framework conceptual model using Visual Basic or Visual C#. Queries against the Entity Framework are represented by command tree queries, which execute against the object context. LINQ to Entities converts Language-Integrated Queries (LINQ) queries to command tree queries, executes the queries against the Entity Framework, and returns objects that can be used by both the Entity Framework and LINQ.


http://msdn.microsoft.com/en-us/library/bb386964.aspx