The limited permissions are granted through the standardization phase and will not be revoked by Ecma International or its successors or assigns during this time.

To view annotations, follow the Ⓐ, Ⓑ, Ⓓ, Ⓡ, Ⓖ, Ⓔ, and ① hyperlinks in the headings.

A key to the markers explains the different types of annotations.

Also included are a variety of hyperlinked cross-references, following the example of Jason Orendorff’s version at This document may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published, and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this section are included on all such copies and derivative works.

However, this document itself may not be modified in any way, including by removing the copyright notice or references to Ecma International, except as needed for the purpose of developing any document or deliverable produced by Ecma International.

This is not the normative ECMAScript Language specification.

The normative spec (ECMA 262) is a PDF file maintained by ECMA TC39 and is available from An auto-generated HTML version is available, too: This is an annotated, hyperlinked, HTML version of Edition 5.1 of the ECMAScript Specification, the source for which is maintained at copyright is asserted on its front matter (everything up through the Table of Contents), but any reuse of its body text (everything following the Table of Contents) must include the normative spec’s copyright notice and license statement.The development of this Standard started in November 1996.The first edition of this Ecma Standard was adopted by the Ecma General Assembly of June 1997.That Ecma Standard was submitted to ISO/IEC JTC 1 for adoption under the fast-track procedure, and approved as international standard ISO/IEC 16262, in April 1998.