1 Introduction

The ECMAScript of the Microsoft web browsers is a dialect of the language defined in the ECMAScript Language Specification (Standard ECMA-262) Fifth Edition [ECMA-262/5], published December 2009. This document describes the level of support provided by the browsers for that specification.

The [ECMA-262/5] specifications contain guidance for authors of webpages, browser users, and user agents (browser applications). This conformance document considers only normative language from the related specifications that applies directly to user agents.