Venkman is the code name for Mozilla's JavaScript Debugger. It aims to provide a powerful JavaScript debugging environment for Mozilla based browsers namely Firefox, Netscape 7.x/9.x and SeaMonkey. Note that it is not included in the Gecko-based browsers such as K-Meleon, Galeon and Netscape 8.x. Venkman has been provided as part of the Mozilla install distribution since October 2001, as well as an extension package in XPI format.


Venkman Introduction
An overview and some practical examples of using the JavaScript Debugger in Web development.
Using Breakpoints in Venkman
This article describes breakpoints in JavaScript and how to use Venkman to set and examine breakpoints.
Learning the JavaScript debugger Venkman
Written by Svend Tofte to the JavaScript programmers who are not familiar with other debugging tools.
Venkman FAQ
Answers to common questions on Venkman.
Venkman Internals
Notes on Venkman source code.
Venkman Development Page
Older news and releases.

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Brief History

In 1998, John Bandhauer was in charge of creating the Netscape 4.x JavaScript debugger. In order to keep things modular, he began by creating a mid-level JavaScript debugging API known as js/jsd. This API augments the existing JavaScript API, providing clients with a useful set of debugger functionality implemented in C. Bandhauer then went on to reflect that API into Java, and create his cross platform front end, eventually producing Netscape JavaScript Debugger 1.0 and 1.1.

In April of 2001, Robert Ginda began work on a JavaScript debugger for Mozilla, called Venkman. Venkman builds on the js/jsd portion of John's 1998 work, exposing it as an XPCOM component. This allows the user interface be written in JavaScript and XUL, which allows Venkman to be fully cross-platform.

Venkman is named after the character Dr. Peter Venkman, played by Bill Murray in the movies Ghostbusters and Ghostbusters II.

Getting Venkman

Firefox and Thunderbird
The latest version of JavaScript Debugger is available from Firefox Add-ons.
Mozilla Suite and SeaMonkey
These releases come with Venkman pre-installed. On Windows, it is an install option; choose Advanced install. Also available from Firefox Add-ons as an extension.
Nvu and KompoZer
JavaScript Debugger extension version 0.9.84 is available from Nvu's downloads page. We encourage you to use the latest available version (or higher) with Firefox instead.
Source Code
The source code for Venkman may be found in Mercurial at the following URL:


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Report a bug in Venkman

If you find a problem with Venkman, please follow directives mentioned at Venkman FAQ section 5.4 and then you may report a bug on JavaScript Debugger component.

JavaScript, Web Development, Developing Mozilla

Original Document Information

  • Author(s): Robert Ginda
  • Other contributors: Doctor Unclear
  • Last Updated Date: July 13, 2007
  • Copyright Information: Portions of this content are © 1998–2007 by individual contributors; content available under a Creative Commons license | Details.