C# 3.0 New Features

1. Implicit typing of local variables, which permits the types of local variables to be inferred from the expressions used to initialize them

2. Extension methods, which make it possible to extend existing types and constructed types with additional methods, outside their definitions

3. Lambda expressions, an evolution of anonymous methods that provide improved type inference and conversions to both delegate types and expression trees

4. Object initializers, which ease construction and initialization of objects

5. Anonymous types, which are tuple types automatically inferred and created from object initializers

6. Implicit typing of arrays, which is a form of array creation and initialization together where the element type of the array is inferred from the initializer

7. Query expressions, which provide a language-integrated syntax for queries that is similar to relational and hierarchical query languages, such as SQL and XQuery