Javascript Versions

There have been several revisions of Javascript/ECMAScript/JScript, and different versions have been deployed in different situations. This table details which versions relate to which browser.

Javascript	Mozilla	JScript	IE	ECMA
JavaScript 1.0	Netscape 2	JScript 1.0	Early IE 3
JavaScript 1.1	Netscape 3	JScript 2.0	Late IE 3	ECMAScript 1 plus switch
JavaScript 1.2	Netscape 4	-	-
JavaScript 1.3	Netscape 4.5	JScript 3.0	IE 4
JavaScript 1.4	Server only	-	-
JavaScript 1.5	Mozilla/Netscape 6	JScript 5	IE 5	ECMAScript 3

warning on IE's "support" of JavaScript 1.5

Submitted by Joe Shelby (not verified) on August 23, 2005 - 20:39.

IE does support JavaScript 1.5, but it doesn't support it in the "language" attribute of the script tag.

If you include the language attribute (which was originally meant to allow a page to gracefully degrade in older browsers, a concept that's increasingly obsolete), you can't have a value greater than "javascript1.2". Anything besides "javascript" or "javascript1.2" and IE will likely not execute the script.