Visual Studio 2010 + Target Framework 3.5. What version of c# compiler will be used?

Question

Question is in title. 3.0 or 4.0?

Answer 1

It will use the C# 4 compiler, so you can still use (some) C# 4 features.

If you want to restrict yourself to C# 3, click on the Advanced button in the project properties Build tab (bottom right) and you can choose the language version you want to use.