Many versions of MooTools, since 1.2.1, and Prototype, since 1.5.1, break the native JSON.stringify() implementation,
either by defining a custom JSON object without a stringify method, or defining a custom Array#toJSON method.
While MooTools and Prototype have addressed native JSON support in their 1.3 and upcoming 1.7 releases, respectively,
both frameworks have done so more than a year and a half after native support for JSON was introduced.