"Why do you want to discard HTML?" If the question is to start to stink and long, I'll try to be simple:
The HTML development to today exists three main disadvantages:
1. It's too easy. Can not adapt to the more network devices and applications now need. For example, mobile phones, PDAs, information appliances can not directly display HTML.
2. Too large. Because the HTML code is not specification and bloated, browsers need to be smart and bulky to display HTML correctly. It is obvious that it is impossible to install a IE6 on your PDA. There is not enough space to keep up with the operation.
3. Data and performance are mixed. If you want to change the display of your page, you must make the HTML again. Displaying the same data for different network devices requires different HTML.
You might say these flaws don't matter to you now, not serious. But society is always in progress, technology is always developing, people always hope that the work is more and more simple, more and more efficient. and the development of network equipment will not stop because of the disadvantage of HTML. Bulky desktop computers will be replaced by more and more lightweight and compact devices. So there needs to be a new language that can describe the data so that all devices are understood (which produces XML), and a language is needed to control performance so that data is displayed correctly on different devices (which produces XSL).
That is, we will certainly use XML to transform data in the future, using XSL to control performance. So what now?
Now, obviously, thousands of HTML pages still need to work, and it's impossible to discard them. And now browsers are not able to express XML documents directly. Even if you can later, what now?
So the consortium developed XHTML. XHTML is a bridge over HTML to XML. It is a transition program that leads people to move towards the norm and XML. Although XHTML has an "X", it does not extend, but adheres strictly to the XML specification on the basis of HTML. It is easy to learn and has little new knowledge.
And XSL, you can now use CSS to implement part of the XSL functionality.
These are the answers to why you should discard HTML. May be said not comprehensive, the main meaning of the.