Alexander G. Oliva Web Page

Alexander G. Oliva: EEL 4781

5 Improvements of xhtml over the current html specification are;

XML was conceived as a means of regaining the power and flexibility of SGML without most of its complexity.Although a restricted form of SGML, XML nonetheless preserves most of SGML's power and richness, and yet still retains all of SGML's commonly used features. While retaining these beneficial features, XML removes many of the more complex features of SGML that make the authoring and design of suitable software both difficult and costly. In XML, it is relatively easy to introduce new elements or additional element attributes. The XHTML family is designed to accommodate these extensions through XHTML modules and techniques for developing new XHTML-conforming modules (described in the forthcoming XHTML Modularization specification). These modules will permit the combination of existing and new feature sets when developing content and when designing new user agents. Alternate ways of accessing the Internet are constantly being introduced. Some estimates indicate that by the year 2002, 75% of Internet document viewing will be carried out on these alternate platforms. The XHTML family is designed with general user agent interoperability in mind. Through a new user agent and document profiling mechanism, servers, proxies, and user agents will be able to perform best effort content transformation. Ultimately, it will be possible to develop XHTML-conforming content that is usable by any XHTML-conforming user agent.

XML hyperlinking goes beyond basic HTML-style hyperlinking with a number of new features, including the ability to create "smart" links without a lot of hand-coded JavaScript. And in XML, links become objects in their own right and can thus be managed like any other objects.

The original linking specification--XLL, or XML Linking Language--is being split into two separate specs: XPointer and Xlink;

XPointer: In HTML it's possible to link to the middle of a page only if the author of that page put an anchor tag there. With XPointer you'll be able to "address to" (not "link to") any part of someone else's text. It's easy to see how this would be useful in working with legal documents, scientific and academic papers, even W3C specifications!

XLink: When a user clicks an HTML hyperlink, the current Web page is replaced by the file being linked to. XLink lets Web builders add behaviors to links. Today, for example, you have to use a bit of JavaScript to make a link pop up a separate window, but XLink lets Web builders code links to perform a variety of actions, including popping up a menu of linking choices.

XML also lets Web builders create Extended Links that work sort of like a Web ring, which is a self-selected group of Web sites relating to the same topic that are navigated through a "next/previous" progression. For lists of related links too long for a popup menu, Web builders could create a linked list that changes from site to site, page to page. Users could click an icon to automatically move to the next member of the ring. Today this would require CGI scripts, but Extended Links offers a standardized, nonproprietary method of creating relationships among resources.

Browser; A set of clients , a set of interpreters, and a set of controllers that manges them. The controller is the central piece of the browser. It interprest both mouse clicks and keyboard input, and calls other components to performother operations as spcified by the user. ie, if the user clicks on a URL or hypertext reference, the controller calls a client to fetch the request document from the remote server on which it resides, and an interpreter to display the document for the user.

Web Server; A server waits for a browser to open a connection and request a specific page. The server then sends acopy of requested item, closes the connection, and waits for the next connection.

HTML; each document is divided into two major parts; a head followed by a body. The head contains details about the document, while the body contains the majority of the information.