[jayd16]

C# has type safe anonymous types.

    //Anonymous type with integer property
    var foo = new {Number = 1};
    //Compile time error if you try to assign a the integer property to a string
    string s = foo.Number;

An object is just a fancy map, after all... These are also immutable by default, which probably makes them even more relevant to this DOA discussion.

[weavejester]

Maps are open, while objects are closed.