XML was created in 1996 by a set of 11 people and it was derived from SGML which stands for Standard Generalized Markup Language. The basic job of XML was to simply store and carry data as it is. The fact that XML uses general terms makes it very easy to understand and use. Its usability also makes it very convenient and a language of choice for a lot of webmasters. A number of languages have been developed recently which are based on XML. These languages are RSS, XHTML, SOAP and Atom. A lot of MS office productivity tools, by default, use XML based files. The processor of XML is also known as a parser. An XML processor typically goes through the code and the passes it on to an application.

The basic difference between the two languages is the goal they have. The basic goal of HTML is to decide how the data in a website will be displayed. The goal of XML is to simply contain the data. The tags and pre-defined codes exist in HTML which decides how a web page will be displayed. In XML, the file that is created has no pre-defined terms or codes. Whatever is written can easily be understood for what it is because it is quite self-explanatory. Words or terms can be created by the webmaster and then be saved in a file. Many website designers create their own terms which can be related to the business of their clients. It is easy for people who do not get HTML too well and think that codes complicate things rather than making it easy to use.

There is also a sense of clarity in XML compared to HTML. HTML needs to be learnt more vigorously by the webmasters than XML. HTML has different tags for providing layout and design of a webpage. It also has a particular structure to the coding which has to be followed while creating a website. HTML is used for displaying online pages which may have graphics, sound or video files. Hypertext links can also be used to view information contained in a website.

Certain websites which are extension to a business require monetary transactions to take place. HTML caters for such requests also. These services include transferring money from one account to another in banking websites, book train or air tickets through travel websites and many similar actions. HTML is also capable of including excel sheets and other such documents directly as part of a website. W3C maintains and keeps modifying HTML by updating it from time to time.

Related posts:

• HTML – Hyper Text Markup Language
• XHTML – An Overview
• Changing HTML into XHTML

History

As with XML, the World Wide Web Consortium (W3C) was the force behind XHTML’s development. When XML was introduced, a two-day workshop was held to discuss whether a new version of HTML in XML was needed. The answer was a resounding “Yes.”

The first W3C Recommendation to be published was XHTML 1.0, which reformulates HTML 4.0.1 in XML and combines the strengths of the two markup languages. The recommendation followed from earlier work on HTML 4.0.1, HTML 4.0, HTML 3.2, and HTML 2.0.

The second W3C Recommendation was XHTML Basic. It boasts of images, forms, basic tables, and object support. XHTML Basic is designed for Web clients that do not support the full set of XHTML features; examples of these clients are mobile phones, PDAs, pagers, and set-top boxes.

The third W3C Recommendation to come out was on the Modularization of XHTML. It provides a means for extending and creating subsets for XHTML. The modular design introduced by this recommendation underscores the invalidity of the “one-size-fits-all” approach nowadays, especially with the advent of Web browsers that vary in capabilities (e.g. cellphone browser vs. desktop PC browser).

The fourth W3C Recommendation was XHTML 1.1 (Module Based XHTML). Here, a new XHTML document type is defined based on the modular design of the third XHTML Recommendation.

Profile

XHTML is a family of current and future document types and modules that contains all of the HTML 4.0.1 elements combined with XML syntax. XHTML is classified as an XML Application, and thus possess many XML features.

XHTML, described by Andrew Tanenbaum as a “language that is Very Picky”, differs itself from HTML by its stricter syntax.

The current version of XHTML that is supported by browsers is XHTML 1.0, a W3C Recommendation discussed earlier. There are three variants to XHTML 1.0:

XHTML 1.0 Strict — used for exceptionally clean structural markup; the CSS (Cascading Style Sheet) language can be used with this variant to get the desired font, color, and layout effects

XHTML 1.0 Transitional — best option for Web authors with webpages meant for general public access; takes advantage of XHTML features including style sheets

XHTML 1.0 Frameset — used to partition the Web browser window into two or more frames

Syntax

The important thing to remember here is that XHTML is extended HTML. This means that writing XHTML code is very similar to writing HTML code. The only difference lies in the fact that XHTML is more strict and more structured than its progenitor.

A good way of familiarizing yourself with XHTML is to get old HTML code and bring it up to XHTML standards. You’ll need to keep in mind several rules:

• All elements must be properly nested.

• All elements must be properly closed.

• All tag names must be in lower case.

• All attribute names must be in lower case.

• All attribute values must be properly quoted.

• The “id” attribute replaces the “name” attribute.

• All images must have alternate (“alt”) text — make the page accessible for devices that don’t load images, or screen-readers for the blind.

• All XHTML documents must have a DOCTYPE declaration, as well as the “html”, “head”, and “body” elements.

• The “title” element must be present within the “head” element.

A good hands-on tutorial on XML can be found at http://w3schools.com

Discpiline and practice will allow you to master XHTML in no time. However, if you don’t want to convert an existing HTML document to XHTML yourself, you can use HTML Tidy, a software that does the transformation for you. Also, you can use Amaya, a web browser and editor that saves HTML documents as XHTML ones.

Related posts:

• Changing HTML into XHTML
• Difference Between HTML And XML
• HTML – Hyper Text Markup Language

Earlier it was HTML then it made the buzz and now the future seems to be of XML. Knowledge of HTML help helps to learn XHTML and the same way XHTML knowledge will help in learning XML.
Below are some simple rules which should be kept in mind while changing your Web design from HTML to XHTML:

• Use All Lowercase Tags:

Use lowercase letters to write alt. Writing is not allowed, so better use .

• Nest Elements Correctly:

HTML is a bit lenient but XHTML is not. An example: It is wrong.. This can be seen in this example You that the bold and italic elements are overlapping. The correct way to nest these elements is: This is right..

• Using End Tags is a must:

Every tag must end with a tag and hence must have an end tag. In the start of a paragraph we use the tag and in the end of the paragraph we must use the tag. Same is the case with li tag and all other tags.

• End Empty Elements:

Generally, no one end empty elements, but you should end empty elements like tag, and you need an end tag for this one too. You can either use to end or you can use an alternative i.e. This can be used in both HTML and XHTML. The same can be used with other empty tags too, such as( hr) tag.

• Use Code for Special Characters

Related posts:

• XHTML – An Overview
• Difference Between HTML And XML
• HTML title tags