ECMAScript 262 And Browser Compatibility

I was curious to check how well the current browsers implement ECMAScript 262 specification. At the time of writing I have the following browsers installed on my machine: Google Chrome (34.0.1847.116 m) Microsoft IE (11.0.9600.17031 / 11.0.7) Mozilla Firefox (28.0) I guess Chrome, IE and Firefox present at least 90% of all desktop browsers. I …