MonoTouch/MonoDroid port of the fantastic JSON.NET library - http://json.codeplex.net
goneflyin/Newtonsoft.Json
Newtonsoft.Json library for MonoTouch/MonoDroid. The official Newtonsoft.Json project can be found here: http://json.codeplex.com/ Going to be expanding this further. Thanks to JamesNK for all his hard work on this project.
C#MIT