I read a pdf document - netduino Getting Started, in "install", it recommended to download and install 3 software:
1.Microsoft Visual C# Express 2010
2.Microsoft .NET Micro Framework v4.1 SDK
3.Netduino SDK v4.1
while, from the latter description, I found "2.Microsoft .NET Micro Framework v4.1 SDK" hasn't been used, is it necessary or not ? If it was necessary, what's the function of it for Netduino ?