Hi Manish,

you can use the global JSON object in nodejs just like in a browser, so there is JSON.parse and JSON.stringify available both on the server and client side when working with mojito. Here you can find some examples:
https://developer.mozilla.org/en/JSON

If you are developing in Mojito and using YUI, I think you should go for YUI3's JSON utility documented with examples here:
http://yuilibrary.com/yui/docs/json/
This will iron out possible JS runtime environment bugs, like browsers bugs/differences for you.

Regards,
Fabian