Newtonsoft Json.NET
Simplify .NET <-> JavaScript communication. The Json.NET librarys allows the simple and safe reading and writing of JSON objects from .NET.
Product product = new Product();
product.Name = "Apple";
product.Expiry = new DateTime(2008, 12, 28);
product.Price = 3.99M;
product.Sizes = new string[] { "Small", "Medium", "Large" };
string output = JavaScriptConvert.SerializeObject(product);
//{
// "Name": "Apple",
// "Expiry": new Date(1230422400000),
// "Price": 3.99,
// "Sizes": [
// "Small",
// "Medium",
// "Large"
// ]
//}
Product deserializedProduct = (Product)JavaScriptConvert.DeserializeObject(output, typeof(Product));