The ten design goals for XML, (somewhat like Moses’ Ten Commandments), are:
1. XML shall be straightforwardly usable over the Internet.
2. XML shall support a wide variety of applications.
3. XML shall be compatible with SGML.
4. It shall be easy to write programs which process XML documents.
5. The number of optional features in XML is to be kept to the absolute minimum, ideally zero.
6. XML documents should be human-legible and reasonably clear.
7. The XML design should be prepared quickly.
8. The design of XML shall be formal and concise.
9. XML documents shall be easy to create.
10. Terseness in XML markup is of minimal importance.
So, in providing reliable global communication, how does XML help with that? According to design goal 1, XML will be usable over the internet. It does not say the internet here in the United States, but the internet in general. This means, that with an internet connection and a little XML know-how, anyone anywhere should be able to send information via TCP/IP that will be recognized by any other computer with an internet connection. It is a simplified way of sharing data across systems, particularly the internet.
As for extending HTTP into the future, I believe that XML will be used in the next version of HTTP. Since HTTP was originally designed as a way to publish and receive HTML pages, it makes sense that the next version of HTTP would be a way to universalize the sending and receiving of XML pages. In other words, maybe the future will see a XML based language for webpages that allows all information to be sent and received reliably every time. Design goals 1, 2 and 4 show how XML will account for these things.
As a tag-based markup language, XML extends the universality of HTML. As a new language, XHTML combines HTML and XML in a way that allows for automated processing, unlike HTML, which was more flexible, and therefore less standard. "XHTML consists of all the elements in HTML 4.01 combined with the syntax of XML. (Wikipedia)" The problem with HTML is that it "addresses content and structure (Rhyno 72)". For websites that have a large number of pages, XML gives these pages a uniformity of syntax that HTML was not capable of. As I read in several different places, HTML was good in the beginning, when the webpages numbered few, and could be modified individually. Now that this is no longer the case, a more standard language had to be invented. So goals 2, 3, 4, 6 and 9 help make this possible.
When researching this particular subject, I was reminded of the cascading style sheets we created for our last exercise. To me, it seems that XML or XHTML and CSS can go hand in hand in preparing for the future of the internet. XHTML will be used to create the pages, in a uniform, consistent format. CSS will be used to create the style for those pages, in a ubiquitous manner. This will in turn make the data more accessible and universal. It will be something that all browsers can read and display correctly every time.
How will XML build upon the browser? Well, as of right now, the majority of browsers support SGML, which is the parent of XML. Since XML is compatible with SGML, I believe that means that the browsers will support XML. Especially since the new dominating language appears to be XHTML, those browsers will need to be XHTML compatible, or they won't support very many pages.
XML and libraries, how it builds upon the building blocks
XML is also preparing us for the future in the way data is stored. Rhyno lists three ways in which XML is useful to libraries, it is well formed, can be validated and checked for consistency and it separates content from presentation. While I have discussed these points in some way already, it is important to see how libraries, 'information containers', will utilize XML based applications for the increasing amount of electronic data it will be storing in the future. I think one of the most important elements for this future is the DTD (document type definition) that XML adopted from SGML. As Rhyno says, "Identifying or authoring the appropriate DTD is one of the most important steps in managing a library's digital collection". DTD is used to describe a document, or a portion of it authored in DTD. This makes it easy to search for the correct type of document within the language, since the tags are universal. When searching through hundreds or thousands of documents, having a universal tag or language is invaluable.
Concluding Thoughts
I appreciate the concise nature of XML, though it can be unforgiving. I believe it is part of the future of the internet, and electronic communications, because of its universality. Just using it in podcasts, my first experience with it, was quite easy. I appreciate how you can just cut and paste the area you need and adapt it for future podcasts. This makes so much more sense than reinventing the wheel each time, i.e. rewriting the code. Instead, the precise language allows for an ordered way to update the podcasts, and keep them in one category. Like Dreamweaver and Nvu, the open-source editor I have used, I believe there will be an editor that allows us to create XML and XHTML just as easily. There's actually probably one out there already that I haven't seen yet!
References:
World Wide Web Consortium. (2006/09/11). Retrieved 9/25/2006 from http://www.w3.org/TR/2006/REC-xml-20060816/
Wikipedia. Retrieved 9/25/2006 from http://en.wikipedia.org/wiki/XHTML
Rhyno, Art. (2005) Introduction to XML. In N. Courtney (Ed.) Technology For The Rest of Us. (71-84). Westport: Libraries Unlimited.
W3Schools Online Web Tutorials. Retrieved 9/25/2006 from http://www.w3schools.com/xhtml/xhtml_why.asp
W3Schools Online Web Tutorials. Retrieved 9/25/2006 from
http://www.w3schools.com/xml/xml_whatis.asp
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