Sent to WebDesign-L on 03/24/00 > I'm trying to teach myself some XML, and up to now I've read a lot of stuff > about its structure, its DTDs, XSL and a bunch of other things. > > What lacks me is some practical uses on XML in the everyday life. I mean, I'm > very interested in the project and I think I'm aware of its importance, but > does someone of you *USE* XML? > > I ran through some tutorials on Webreference but I'd like some more? Any > suggestions? Great question, Antonio. XML is not a mark-up language in the same sense as HTML. XML is more of a language created to describe other languages. In theory, you can use XML to output HTML, ASP, Perl, or pretty much any other ASCII-based (text-based) language. [You can almost think of HTML as a subset of XML, although this would be an example of the child (HTML) coming before the parent (XML).] From the back cover of "XML, A Manager's Guide": "XML provide[s] a standardization for specifying the meaning of information exchanged over networks." This refers directly the concept of XML as a meta-language, or a language that describes and defines other languages. Book: XML, A Manager's Guide; by Kevin Dick ISBN: 0-201-43335-4 You can also use XML to create subset languages like XUL, SVG, and XHTML. XUL (Extensible User-Interface Language) was developed to output custom interfaces, GUIs, and interactions for the Mozilla browser and Mozilla-based web applications. SVG (Scalable Vector Graphics) is a subset of XML that allows you to output vector-based illustrations. For instance, you could control your vector-based illustration with SVG and apply meaning to the related data with XML. Let's say you have a vector-based map of New York City written in SVG. By using XML, you can control the related data (street names, building names, etc.). You can even store this data in a database which is accessed by XML and input into your SVG map file. XHTML is a subset of XML that defines standards for outputting HTML using XML. This will likely be the bulk of the actions performed using XML in the near future, as people start converting their web sites from static HTML pages to (and even dynamically generated HTML using CGI, ASP, JSP, etc) to XML-based pages. SVG: http://beta1.adobe.com/svgpreview_alpha/SVG/main.html http://www.w3.org/Graphics/SVG/ XUL: http://www.mozilla.org/docs/xul/xulnotes/ XHTML: http://www.w3.org/TR/xhtml1/ What's even more important about XML is its role in the emerging web applications market. I expect Mozilla to take the lead in cross-platform web application development, as it's very extensible, has a completely scriptable DOM (Document Object Model), and is based on open source code, which allows developers to compile very specific versions of Mozilla to fit their exact need(s). Examples would be a distributed kiosk network that needs to be very secure (ATMs, E-commerce kiosks, etc.) and desktop web applications (business-to-business web-based tools, web-enabled consumer desktop applications, web-enabled educational CD-ROMs, etc.). Here's some examples of using Mozilla as a web application environment. We're currently working on a script editor (like BBEdit or HomeSite) that runs/loads remotely over the Internet. Because it uses Mozilla as its "application virtual machine", anyone with Mozilla installed can use the script editor. The editor is completely cross-platform because it inherits this feature from the many Mozilla ports (Win 95/98/NT, Mac OS 8/9/X, Amiga, Linux, Unix, etc.) Script Editor: http://www.alphanumerica.com/projects/mozilla/script_editor/ [Note: If you're testing this, please read the instructions/warnings carefully. It's very pre-beta.] What does this mean for web application development? It means that developers no longer have to build multiple versions of their [web] application for their client, should the client be deploying on multiple operating systems. Instead, the developer can develop using Mozilla as the application framework, and deploy one piece of code. It also means that developers can get away from the inherently closed development environments of Internet Explorer and Netscape. Additionally, since Mozilla is open source, the developer can avoid the costs associated with using a closed development platform -- costs like Microsoft's Developer Network (MSDN), which can be thousands of dollars per year or more depending on how many developers you have. Web Apps: http://webapps.editthispage.com/ http://davenet.userland.com/2000/03/12/whatIsAWebApplication But, back to XML. By using XML and Mozilla together, you can create a very powerful web application that is exactly suited for your needs. This web application will inherit the standards-compliancy of Mozilla, and will run on almost every operating system in use today. Understand that this is a whole new world of the web we are entering. In 3-5 years, HTML will likely not even be used to create web sites. Instead, we'll have a distributed web application (a browser) that updates itself automatically from your chosen service provider, whether that be AOL, your local or national ISP, or any one of the emerging ASPs (Application Service Providers) that are building web application solutions for consumer and business needs. While HTML still may be used for page display, it will likely be generated using XML (XHTML). The web may even abandon HTML in favor of the more adaptable combination of XML and XSL (XML Stylesheet Language). -- Cameron Barrett Senior Information Architect Alphanumerica, Inc. http://www.alphanumerica.com (work) http://www.camworld.com (play) +----------------------------------------------------------------------+ more info about webdesign-l: http://www.hesketh.com/lists/