Robert Nyman has setup a really nice test suite for JavaScript 1.6, 1.7, and 1.8+ features such as getters/setters, Object.defineProperty, Object.getPrototypeOf, new String extras, and JSON.

It includes compatibility tables, and will try to run the tests on your browser to give you feedback. It also includes sample code to check web browser support that you can use in your own projects.

• Introduction to the tests
• Demos of getter and setters in JavaScript
• JavaScript 1.8.1 tests
• Native JSON tests

Nice job Robert!