Anders Hejlsberg's C# 4.0 REPL

Question

During the last 10 minutes of Ander\'s talk The Future of C# he demonstrates a really cool C# Read-Eval-Print loop which would be a tremendous help in learning the language.

Answer 1

To update on this old question c# REPL is now available as part of Visual studio IDE (starting VS 2015 update 1).

Introducing the Visual Studio 'C# REPL'