Netscape has made the source of the Communicator product available (which includes the Navigator browser). You can download this from the Netscape web site and participate in the development of the browser project. Netscape 6.0 is only just released for public use but is likely to contain some bugs.

We refer to this browser consistently as Netscape regardless of whether you are running Communicator or any other packaged version.

Here is a brief guide to versions of Netscape vs. JavaScript:

Note that version 5.0 never shipped although if you search on the web you can find some installable binaries that may satisfy your curiosity regarding browser history. Some reports suggest that those version 5.0 browsers only supported JavaScript 1.3. Because Mozilla is factored into components, it's feasible that you could build any version of the browser with whatever version of JavaScript you want.

Many values that Netscape exposes as JavaScript properties reflect the value of an HTML tag attribute. Likewise, many of its special objects are counterparts to the HTML tags. However it does not map objects so completely or consistently to HTML tags as the MSIE browser. Nor does it support the attributes and style mechanisms as elegantly.

Where the information is available, we have indicated the version number of JavaScript (or JScript) when HTML tags and attributes became accessible as objects or properties. In many cases, this may be a later version than when the instantiating HTML tag or attribute was first supported by the browser.

We constructed many scripts to inspect and enumerate the various properties of the objects in the MSIE and Netscape browsers. These uncovered many object types and properties that were hitherto undocumented. They might have been available in earlier versions of the browser. However, where language elements were discovered for the first time, they are initially documented as being available from version 4 of Netscape. A limited amount of further testing was applied where it was suspected that language elements may have been available in earlier releases and the availability modified accordingly.

Version 5 of Netscape was scrapped because its codebase became too unwieldy to work with. There seems little point in documenting its peculiarities. Netscape version 6.0 was in beta trials and until PR3 was so unstable and crash-prone that most of our testing bore little fruit. Right at the point where content was being finalized for publication Netscape 6.0 was released as a final product. It is clearly still a work in progress and there are quite a few non-working components. It looks good though. The potential for exercising the DOM standard document navigation is really exciting. There is a great deal yet to discover about the new browser and it will stabilize as bugs get fixed and new releases are shipped.

Perhaps browser versions may become less important as they converge on a single standard benchmark of functionality. For the time being, current practice suggests that version 4 browsers of both traditions are rapidly being taken over by version 5 MSIE browsers. Version 2 and 3 of MSIE and Netscape have declined to such small usage levels as to not require any further serious attempts to support them on new projects. Netscape 6.0 may win back some market share but only if its bugs are fixed quickly. Version 6.0 of MSIE is about to go to beta testers and the standards bodies are still some way ahead of the browser manufacturers so there is a long way to go yet.

Warnings:

• Netscape 2.02 does not cope gracefully with dollar signs in identifier names.

Cross-references:

Wrox Instant JavaScript - page - 14

Web-references:

http://www.mozilla.org/ http://www.netscape.com/ http://home.netscape.com/browsers/6/index.html