LINQ to JSON in .net 4.0 Client Profile <p>How would I go about about using LINQ to JSON in the .net 4 Client Profile in C#. I'd like to query certain json responses as shown in <a href="http://blogs.msdn.com/b/mikeormond/archive/2008/08/21/linq-to-json.aspx" rel="nofollow" title="msdn blog">msdn blog post</a> without having to write out a contract (datacontract, servicecontract, etc). I really only need to query(read) the response, I don't need to modify the json response. (Also would a datacontract be faster than LINQ to JSON?)</p> <p>Alternatively I could use XML or the full .net 4 framework, but I'm hoping that this can be avoided. I can use external libraries if it's better than installing the whole framework.</p>