This page give a short overview of the JavaScript language, available engines and JavaScript enabled products. Some of them are explained on separate pages demonstrating the usage of JavaScript in general and JsUnit especially in their context.

JavaScript Language

JavaScript is normally recognized as scripting language for browsers only. While the the most browsers understand JavaScript to some extent, the language itself is not limited for browser usage. A lot of people also accuse the language of the reason for browser incompatibilities or security holes, but this is not true wither. JavaScript itself has no idea of the DOM or of a file system. Any functionality built into the language concerning these topics are add-ons by the vendors. Also a lot of vendors have not implemented the complete JavaScript standard arising a lot of incompatibilities, too. Therefore you have always to separate between the language itself and the version released from a vendor.

ECMAScript is the official name of the language commonly called "JavaScript". ECMA is an international, industry association and dedicated to the standardization of information and communication systems. The language is specified in the ECMA-262 document currently in the 3rd edition from 1999. This edition introduced exceptions into the language. Unfortunately the standard does not define any functionality or properties to retrieve the call stack. A new edition 4 of ECMAScript is upcoming, but not ready yet.

JavaScript is the ECMAScript version of Netscape. To be honest, JavaScript was developed by Netscape and introduced with the Netscape 2.0 browser. Starting with JavaScript 1.4 Netscape also implemented the exceptions. Today Mozilla.org is developing in accordance with ECMA a new version 2.0 of JavaScript, that will implement the features of an upcoming 4th edition of the ECMA standard.

The JsUnit library has to use exceptions. Exceptions were part of the third ECMA language draft and therefore not everywhere available. The JsUnit scripts are only available on systems that support exceptions. Additionally the scripts try to expose the call stack in case of an error. This call stack is also subject of compatibility and have changed in various versions of the language implementations of the different vendors. Unfortunately the ECMA specification does not have any definition.

Script Engines

Writing a JavaScript interpreter according the ECMA specification is quite a lot of work. Therefore most JavaScript engines are used in more than one product. The most popular engines can be embedded freely in your own applications. Mozilla.org has two JavaScript engines to offer as Open Source, Microsoft's engine is also available for applications as system service via COM.

Mozilla.org

Mozilla.org provides two script engines, one implemented in C (SpiderMonkey) and one in Java (Rhino). SpiderMonkey is used also in the Mozilla browser.

Microsoft JScript

Microsoft's JavaScript implementation named JScript is part of the Windows Script engine. This engine is able to run a lot of languages, JScript is just one among others. Any application may embed the script engine and process scripts in any of the registered languages.

Microsoft Windows Script
JScript enabled applications
Development and Debugging with JScript
- Windows Script Debugger
- Microsoft Visual InterDev

JavaScript enabled products

There are a lot of products that are able to process a JavaScript flavor. I have listed all products that I am aware of.

Product	Vendor	Language	Engine	JsUnit Version	Comment
Bean Scripting Framework	IBM	JavaScript 1.5	Rhino, JScript	?	uses other scripting engines
Communiqué 2.x	Day International	ECMAScript	own	-	no exceptions
Communiqué Unify (3.x)	Day International	JavaScript 1.5	Rhino	1.2 ?
deployZone Application Server	deployZone	JavaScript 1.5	Mochascript	?
Director MX 2004	Adobe (Macromedia)	Lingo	SpiderMonkey	?
DMDScript	Digital Mars	ECMA-262, v3	own	?	?
Enterprise Server 3.x	Netscape	JavaScript 1.2	Netscape	-	no exceptions
FESI	Jean-Marc Lugrin	ECMA 262, v2	own	-	no exceptions
Flash 5.x	Macromedia	ActionScript 5	own	-	no exceptions
Flash MX	Macromedia	ActionScript 6	own	-	no exceptions
GoLive 5	Adobe	ECMA 262, v3	SpiderMonkey	?
IceStorm Browser	IceSoft	?	?	?
Internet Explorer 4.x	Microsoft	JScript 3.0	JScript	-	no exceptions
Internet Explorer 5.x	Microsoft	JScript 5.0	JScript	1.0, 1.1, 1.2
Internet Explorer 6.x	Microsoft	JScript 6.0	JScript	1.0, 1.1, 1.2
Internet Information Server 4.x	Microsoft	JScript 3.0	JScript	-	no exceptions
Internet Information Server 5.x	Microsoft	JScript 5.0	JScript	1.0, 1.1, 1.2
iPlanet Web Server, Enterprise Edition 4.x	iPlanet	JavaScript 1.4	Netscape	1.0	no call stack
JANET	Steve Newman	JavaScript 1.4	own	?	JavaScript for .NET
KJSCMD 0.3	KDE.org	ECMA 262, v?	KJS	1.2	no call stack
Konqueror 1.9.8	KDE.org	ECMA 262, v?	KJS	1.2 ?	no call stack
Konqueror 3.1.3	KDE.org	ECMA 262, v?	KJS	1.2	no call stack
Konqueror 3.5.2	KDE.org	ECMA 262, v?	KJS	1.2	no call stack
LiveMotion 1	Adobe	ActionScript 4	?	-	no exceptions
LiveMotion 2	Adobe	Automation Script 2	?	?
Metamerge Integrator	Metamerge	JavaScript 1.5	Rhino	1.2 ?
Mozilla Firefox 0.8x	Mozilla.org	JavaScript 1.5	SpiderMonkey	1.0, 1.1, 1.2	<
Mozilla Firefox 1.x	Mozilla.org	JavaScript 1.5	SpiderMonkey	1.0, 1.1, 1.2
Navigator 4.x	Netscape	JavaScript 1.3	-	-	no exceptions
Navigator 6.x	Netscape	JavaScript 1.5	SpiderMonkey	1.0, 1.1, 1.2	is Mozilla 0.81
Navigator 7.x	Netscape	JavaScript 1.5	SpiderMonkey	1.0, 1.1, 1.2	is Mozilla 1.0 RC2
NGS JavaScript Interpreter 0.2.5	Markku Rossi	JavaScript 1.4	own	-	bugs in exceptions
NJS JavaScript Interpreter 0.3	Brian Basset	JavaScript 1.4	-	-	fork of NGS 0.2.5
Notes 5.x	Lotus	LiveScript x	own	?
Obtree C4	IXOS-Obtree	JavaScript 1.5	SpiderMonkey	1.2	no call stack support
One-to-One 5.x	BroadVision	JavaScript 1.4	1.0	Netscape	OEM of iPlanet 4.x
One-to-One 6.x or newer	BroadVision	?	?	?	is now J2EE server
Opera 4.x	Opera	ECMAScript 2	own	-	no exceptions
Opera 5.x	Opera	ECMAScript	own	-	exceptions buggy, no call stack
Opera 6.x	Opera	ECMAScript	own	?	follows ECMA-262, 3rd, no call stack
Opera 7.x	Opera	ECMAScript	own	?	follows ECMA-262, 3rd, no call stack
Opera 8.x	Opera	ECMAScript	own	1.2	follows ECMA-262, 3rd, no call stack
Rhino 1.5	Mozilla.org	JavaScript 1.5	Rhino	1.2	no call stack support
Safari	Apple	ECMA 262, v?	KJS	1.2 ?	no call stack support
SAP Web Application Server	SAP	?	?	?
ScriptEase Desktop	Nombas	ECMA 262, v3	ScriptEase	?	?
SpiderMonkey 1.5	Mozilla.org	JavaScript 1.5	SpiderMonkey	1.0, 1.1, 1.2	no call stack support
Sun ONE Web Server 6.0	Sun	-	-	-	JavaScript dropped
Visual InterDev 6.0	Microsoft	JScript 5.0	JScript	1.0, 1.1, 1.2
Windows Script 5.x	Microsoft	JScript 5.x	JScript	1.0, 1.1, 1.2
Windows Script Host 1.x	Microsoft	JScript 3.0	JScript	-	no exceptions
Windows Script Host 2.x	Microsoft	JScript 5.0/5.5	JScript	1.0, 1.1, 1.2