Datasheet

Chapter 1: What Is JavaScript?

As of 2008, the five major web browsers (Internet Explorer, Firefox, Safari, Chrome, and Opera) all

comply with the third edition of ECMA - 262. Only one, Firefox, has made an attempt to comply with the

fourth edition of the standard. Internet Explorer 8 was the first to start implementing the unfinished

ECMAScript 3.1 specification. The following table lists ECMAScript support in the most popular web

browsers:

Browser ECMAScript Compliance

Netscape Navigator 2 —

Netscape Navigator 3 —

Netscape Navigator 4 – 4.05 —

Netscape Navigator 4.06 – 4.79 Edition 1

Netscape 6+ (Mozilla 0.6.0+) Edition 3

Internet Explorer 3 —

Internet Explorer 4 —

Internet Explorer 5 Edition 1

Internet Explorer 5.5 - 7 Edition 3

Internet Explorer 8 Edition 3.1 *

Opera 6 – 7.1 Edition 2

Opera 7.2+ Edition 3

Safari 1 - 2.0.x Edition 3 *

Safari 3+ Edition 3

Chrome 0.2+ Edition 3

Firefox 1 – 2 Edition 3

Firefox 3 Edition 4 *

Firefox 3.1 Edition 4 *

Firefox 4.0 * * Edition 4

*Incomplete implementations

**Planned

c01.indd 6c01.indd 6 12/8/08 11:21:51 AM12/8/08 11:21:51 AM