JSON polyfill: JSON 2 or JSON 3?

Question

I need a JSON polyfill to support IE 7 and some IE 8 and IE 9 modes. Should I pick JSON 2 or JSON 3? Obviously JSON 3 is a more modern implementation, but for example a site

Answer 1

HTML5 Please has updated their JSON page to include JSON 3 as the main polyfill for use, with JSON 2 taking a backseat as the older replacement.