In 1998, John Bandhauer was in charge of creating the Netscape 4xJavaScript debugger. In order to keep things modular, he began by creating a mid-level JavaScript debugging application programming interface (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-platformfront end, eventually producing Netscape JavaScript Debugger 1.0 and 1.1.[1]
In April 2001, Robert Ginda began work on a JavaScript debugger for Mozilla, called Venkman. Venkman builds on the js/jsd portion of Bandhauer'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.[1]