Json.NET
A popular high-performance JSON framework for .NET
Serialize and deserialize any .NET object with Json.NET's powerful JSON serializer. Create, parse, query and modify JSON using Json.NET's JObject, JArray and JValue objects. Query JSON with an XPath-like syntax. 50% faster than DataContractJsonSerializer, and 250% faster than JavaScriptSerializer. Json.NET makes the simple easy and the complex possible. If you need it, Json.NET supports converting between XML and JSON. Json.NET is open source software and is completely free for commercial use...