XML Browsers

Creating a true XML browser is not easy. Besides supporting XML, the browser would have to support a style language such as CSS or XSL. It also should support a scripting language, such as JavaScript. These are heavy requirements for most third-party vendors, so the true XML browsers out there are few. In fact, no complete, general XML browsers currently exist. None of the browsers listed here validate XML documents—they just check for well-formedness—but a few come close.

Internet Explorer 5

Whether you love or hate Microsoft, the fact remains that Internet Explorer is the most powerful XML browser available now; you currently can get it at http://www.microsoft.com/windows/ie/default.htm.

Internet Explorer can display XML documents directly, as you saw in Figure 1.2, and also can handle them in scripting languages (JScript, Microsoft's version of JavaScript, and Microsoft's VBScript are supported). There is good support for style sheets and other features such as the <XML> element, which lets you create XML data islands into which you can load XML documents, and ways of binding XML to ActiveX Data Object (ADO) database recordsets.

Internet Explorer 5.5, in preview at this writing, also supports additional XML features, such as the XPath specification. There's no question that Microsoft's XML commitment is strong—XML has been integrated even into the Office 2000 suite of applications—but Microsoft sometimes swerves significantly from the W3C standards (that is, when Microsoft isn't writing those standards itself).

Netscape Navigator 6

Netscape has just released the preview version of Netscape Navigator 6 (available at http://www.netscape.com/download/previewrelease.html), which has significant XML support. You can see Netscape Navigator 6 at work back in Figure 1.3. This preview version is based on Netscape's open source Mozilla browser, which you can pick up at http://www.mozilla.org. Unfortunately, both Mozilla and the preview version of Netscape Navigator 6 have a reputation for crashing machines frequently.

As with Internet Explorer, support for style sheets is good in Netscape Navigator. The preview version of Netscape Navigator 6 also supports the XML-based User Interface Language (XUL), which lets you configure the controls in the browser. In fact, the preview version's user interface is based on XUL. More XML features will come in Netscape 6, but right now documentation is virtually nonexistent.

Jumbo

One of the more famous true XML browsers that exist is Jumbo, an XML browser designed to work with XML and the CML. You can pick up Jumbo for free at http://www.xml-cml.org/jumbo.html. This browser not only can display XML (although not with style sheets), but it also can use CML to draw molecules, as you see in Figure 1.10.

Relatively few real XML browsers exist, but there are a large number of XML parsers. You can use these parsers to read XML documents and break them up into their component parts.