What Is ECMAScript?

By: Dusty Arlia
Published on July 16, 2012
Last Updated on Wednesday, July 08, 2015 at 7:11 PM
Total Updates: 5

ECMAScript is the official JavaScript specification which is developed and maintained by an international standards organization called Ecma International.

ECMAScript is based on several originating technologies, the most well known being JavaScript and Jscript. The language was invented by Brendan Eich at Netscape and first appeared in that company's Navigator 2.0 browser. It has appeared in all subsequent browsers from Netscape and in all browsers from Microsoft starting with Internet Explorer 3.0.

ECMAScript is an object-oriented programming language. It can perform computations and manipulate objects on the host computer. Within the client-side environment, specific host objects have certain properties that can be accessed and functions that can be called from an ECMAScript program.

The development of ECMAScript began in November 1996 and the first edition was adopted by the Ecma General Assembly in June of 1997.

The original Ecma Standard was submitted to ISO/IEC JTC 1 for adoption and approved as international standard ISO/IEC 16262, in April 1998.

The Ecma General Assembly approved the second edition of ECMA-262 to keep it fully aligned with ISO/IEC 16262. Changes between the first and the second edition were just editorial.

The third edition of the ECMA Standard was adopted by the Ecma General Assembly in December 1999 and published as ISO/IEC 16262:2002 in June 2002. The third edition of the standard introduced powerful regular expressions, better string handling, new control statements, try/catch exception handling, tighter definition of errors, formatting for numeric output and minor changes in anticipation of future internationalization and growth.

Since the third edition, ECMAScript has achieved massive adoption. It is supported by essentially all web browsers. The fourth edition of ECMAScript was not fully completed or published, but it did show progression in the evolution of the language.

The fifth edition of ECMAScript (published as ECMA-262 5th edition) codifies de facto interpretations of the language specification that have become common among browser implementations and adds support for new features that have emerged since the publication of the third edition. Such features include accessor properties, reflective creation, and inspection of objects, program control of property attributes, additional array manipulation functions, support for the JSON object encoding format, and a strict mode that provides enhanced error checking and program security.

The latest edition, ECMA Standard 5.1, is fully aligned with third edition of the international standard ISO/IEC 16262:2011.

ECMAScript is a widely adopted language and its evolution is not complete. Significant technical enhancement will continue with future editions.


ECMAScript® Language Specification. (2011). Retrieved March 4, 2013, from