This document provides an overview of Microsoft Silverlight, including what it is, its features, controls, architecture and new features in C# 3.0 that can be used with Silverlight. Some key points: - Silverlight is a browser plugin that allows development of rich Internet applications using .NET features like XAML and C# for cross-browser and cross-platform applications. - It supports common controls, layout managers, animations and multimedia playback. Languages supported include C#, VB.NET, JavaScript initially and dynamic languages later. - New C# 3.0 features that enhance development include implicit typing, object initializers, lambda expressions, extension methods and LINQ for querying data.