| Many Web pages today are poorly written. | | | | XHTML that is supported by browsers is XHTML 1.0, |
| Syntactically incorrect HTML code may work in most | | | | a W3C Recommendation discussed earlier. There are |
| browsers even if it doesn't follow HTML rules. | | | | three variants to XHTML 1.0: XHTML 1.0 Strict - used |
| Browsers employ heuristics to deal with these flawed | | | | for exceptionally clean structural markup; the CSS |
| Web pages; however, Web-enabled wireless devices | | | | (Cascading Style Sheet) language can be used with |
| (such as PDAs) can't accommodate these hefty Web | | | | this variant to get the desired font, color, and layout |
| browsers. The next step in HTML's evolution comes | | | | effects |
| in the form of XHTML (eXtended Hypertext Markup | | | | XHTML 1.0 Transitional - best option for Web |
| Language), which is basically a combination of HTML | | | | authors with webpages meant for general public |
| and XML.HistoryAs with XML, the World Wide Web | | | | access; takes advantage of XHTML features including |
| Consortium (W3C) was the force behind XHTML's | | | | style sheets |
| development. When XML was introduced, a two-day | | | | XHTML 1.0 Frameset - used to partition the Web |
| workshop was held to discuss whether a new | | | | browser window into two or more framesSyntaxThe |
| version of HTML in XML was needed. The answer | | | | important thing to remember here is that XHTML is |
| was a resounding "Yes."The first W3C | | | | extended HTML. This means that writing XHTML |
| Recommendation to be published was XHTML 1.0, | | | | code is very similar to writing HTML code. The only |
| which reformulates HTML 4.0.1 in XML and combines | | | | difference lies in the fact that XHTML is more strict |
| the strengths of the two markup languages. The | | | | and structured than its progenitor.A good way of |
| recommendation followed from earlier work on HTML | | | | familiarizing yourself with XHTML is to get old HTML |
| 4.0.1, HTML 4.0, HTML 3.2, and HTML 2.0.The second | | | | code and bring it up to XHTML standards. You'll need |
| W3C Recommendation was XHTML Basic. It boasts | | | | to keep in mind several rules:All elements must be |
| of images, forms, basic tables, and object support. | | | | properly nested. |
| XHTML Basic is designed for Web clients that do not | | | | All elements must be properly closed. |
| support the full set of XHTML features; examples of | | | | All tag names must be in lower case. |
| these clients are mobile phones, PDAs, pagers, and | | | | All attribute names must be in lower case. |
| set-top boxes.The third W3C Recommendation to | | | | All attribute values must be properly quoted. |
| come out was on the Modularization of XHTML. It | | | | The "id" attribute replaces the "name" attribute. |
| provides a means for extending and creating subsets | | | | All images must have alternate ("alt") text -- make |
| for XHTML. The modular design introduced by this | | | | the page accessible for devices that don't load |
| recommendation underscores the invalidity of the | | | | images, or screen-readers for the blind. |
| "one-size-fits-all" approach nowadays, especially with | | | | All XHTML documents must have a DOCTYPE |
| the advent of Web browsers that vary in capabilities | | | | declaration, as well as the "html", "head", and "body" |
| (e.g. cellphone browser vs. desktop PC browser).The | | | | elements. |
| fourth W3C Recommendation was XHTML 1.1 | | | | The "title" element must be present within the |
| (Module Based XHTML). Here, a new XHTML | | | | "head" element.A good hands-on tutorial on XHTML |
| document type is defined based on the modular | | | | can be found at and practice will allow you to master |
| design of the third XHTML | | | | XHTML in no time. However, if you don't want to |
| Recommendation.ProfileXHTML is a family of current | | | | convert an existing HTML document to XHTML |
| and future document types and modules that | | | | yourself, you can use HTML Tidy, a software that |
| contains all of the HTML 4.0.1 elements combined | | | | does the transformation for you. Also, you can use |
| with XML syntax. XHTML is classified as an XML | | | | Amaya, a web browser and editor that saves HTML |
| Application, and thus possess many XML | | | | documents as XHTML ones.Phillip Kimpo Jr. is a |
| features.XHTML, described by Andrew Tanenbaum | | | | member of the Association for Computing Machinery |
| as a "language that is Very Picky", differs itself from | | | | (ACM). |
| HTML by its stricter syntax.The current version of | | | | |