The major theme for C# 4.0 is dynamic programming. Increasingly, objects are “dynamic” in the sense that their structure and behavior is not captured by a static type, or at least not one that the compiler knows about when compiling your program. Some examples include

• 　　objects from dynamic programming languages, such as Python or Ruby

• 　　COM objects accessed through IDispatch

• 　　ordinary .NET types accessed through reflection

• 　　objects with changing structure, such as HTML DOM scr ipt objects

• 　　data readers and other user defined dynamic objects

While C# remains a statically typed language, we aim to vastly improve the interaction with such objects.