Overview

HyperText Markup Language (HTML) is a prominent markup language for web pages. By denoting parts of text as links, headings, lists, paragraphs an so forth, it provides a meaning to describe the text-based information in a document. It also allows the usage of text with interactive forms, embedded images and other objects. The format for HTML is such that it is written in the form of tags inside an angle bracket. For example, .HTML is also very likely to be used to refer to a MIME type text whether in its XML-descended form or its form descended directly from SGML. It even has the ability describe to a certain degree, the appearance and semantics of a document or component including the addition of scripting language codes such as (javascripts) which alters the behavior of web browsers and other HTML processes.

HTML markup is basically made up of elements which consist of two basic properties, contents and attributes. For a HTML document to be valid, each attribute and element content have restrictions they have to follow. Elements usually start with a tag <Element> and an end tag </Element>

History

Tim Berners-Lee, a contractor at CERN planned and prototyped a system for CERN researchers to use and share documents which is called ENQUIRE in 1980. Berners-Lee and CERN data system engineer Robert Cailliau each handed up separate proposals for an Internet-based system than works basically like ENQUIRE in 1989. A year passed and the two geniuses worked on a joint proposal for the WorldWideWeb (W3) project which was finnaly accepted by CERN.

First Specifications

HTML Tags was the first publicly released description of HTML on the internet by Berners-Lee himself in late 1991. In his descriptions, he mentioned 22 elements comprising the initial and relatively design of HTML. However only 13 of those elements remains in HTML 4.

Berners considered HTML as an application of SGML but it never was publicly mentioned until a proper and correct statement was given on the two almost similar but never the same systems. It was on the first proposal for an HTML specification by the IETF named “Tim Berners-Lee and Dan Connolly’s Hypertext Markup Language” Internet-Draft. In the draft included the SGML document type definition to define its grammar. However, this draft expired after six months but was still ever important and notable for its acknowledgement by the NSCA Mosaic browser’s custom tag for embedding in-line images. Similarly, Dave Raggett's competing Internet-Draft, "HTML+ (Hypertext Markup Format)", from late 1993, suggested standardizing already-implemented features like tables and fill-out forms.

When the drafts of HTML and HTML+ expired in the early 1994, the IETF created a HTML Working Group which then successfully created HTML 2.0, the first HTML specifications for future implementations to be based on. The HTML 2.0 included ideas from HTML and HTML+ drafts and its basics. There was never a HTML 1.0 and the version 2.0 designation was to distinguish the new version from other previous drafts. Future advancing of the IETF was put to block by competing interest. Since 1996, with commercial software vendors by the World Wide Web, the HTML specifications have been maintained. So it was till the year 2000 when HTML also became an international standard (ISO/IEC 15445:2000). The last published HTML specifications was the HTML 4.01 Recommendations released in 1999 and its issues and errors later in year 2001.

July, 1993: Hypertext Markup Language, was published at IETF working draft (that is, not yet a standard).

November, 1995: HTML 2.0 published as IETF Request for Comments:

• RFC 1866,
• supplemented by RFC 1867 (form-based file upload) that same month,
• RFC 1942 (tables) in May 1996,
• RFC 1980 (client-side image maps) in August 1996, and
• RFC 2070 (internationalization) in January 1997;

A proposal of HTML 3.0 standard was proposed to the IETF by Dave Raggett and the new W3C in April 1995. It stated many possible capabilities that were in his HTML+ proposal such as support for tables, text flow, display of mathematical elements and etc. Every other thing went well except for the fact that it was too complicated at that time to be implanted. Due to lack of browser support however, HTML 3.1 was never officially proposed, and the next standard proposal was HTML 3.2.

January 14, 1997: HTML 3.2, published as a W3C Recommendation.

HTML 3.2 was never submitted to the IETF, whose HTML Working Group closed in September 1996; it was instead published as one of the W3C's first "Recommendations" in early 1997. Mathematical support as proposed by HTML 3.0 finally came about years later with a different standard, MathML. December 18, 1997: HTML 4.0, published as a W3C Recommendation. It offers three "flavors":

• Strict, in which deprecated elements are forbidden,
• Transitional, in which deprecated elements are allowed,
• Frameset, in which mostly only frame related elements are allowed;

HTML 4.0 (initially code-named "Cougar") likewise adopted many browser-specific element types and attributes, but at the same time began to try to "clean up" the standard by marking some of them as deprecated, and suggesting they not be used. Minor editorial revisions to the HTML 4.0 specification were published in 1998 without incrementing the version number and further minor revisions as HTML 4.01.

April 24, 1998: HTML 4.0 was reissued with minor edits without incrementing the version number.

December 24, 1999: HTML 4.01, published as a W3C Recommendation. It offers the same three flavors as HTML 4.0, and its last errata were published May 12, 2001. HTML 4.01 and ISO/IEC 15445:2000 are the most recent and final versions of HTML. May 15, 2000: ISO/IEC 15445:2000 ("ISO HTML", based on HTML 4.01 Strict), published as an ISO/IEC international standard.

January 22, 2008: HTML 5, published as a Working Draft by W3C.

Overview

The Extensible Hypertext Markup Language, or XHTML, is a markup language that has the same depth of expression as HTML, but also conforms to XML syntax.

Whereas HTML is an application of Standard Generalized Markup Language (SGML), a very flexible markup language, XHTML is an application of XML, a more restrictive subset of SGML. Because they need to be well-formed, true XHTML documents allow for automated processing to be performed using standard XML tools—unlike HTML, which requires a relatively complex, lenient, and generally custom parser. XHTML can be thought of as the intersection of HTML and XML in many respects, since it is a reformulation of HTML in XML. XHTML 1.0 became a World Wide Web Consortium (W3C) Recommendation on January 26, 2000. XHTML 1.1 became a W3C recommendation on May 31, 2001.

XHTML is a proposed successor to HTML. As such, many consider XHTML as the current or latest version of HTML. However, XHTML is a separate recommendation; the W3C continues to recommend the use of XHTML 1.1, XHTML 1.0, and HTML 4.01 for web publishing, and HTML 5 is currently being actively developed.

XHTML 1.0

Known as the original W3C Recommendation, in other words, the reformulation of HTML 4.01 in XML, XHTML version 1.0 consist of 3 different DTD’s, each equal in scope to their respective HTML 4.01 versions. The 3 DTD’s are :-

a) XHTML 1.0 Strict is similar to HTML 4.01 Strict following XML rules
b) XHTML 1.0 Frameset is also similar to HTML 4.01 Frameset which allows the defining of HTML frameset , a common practice in versions of HTML 4.
c) XHTML 1.0 Transitional again similar to HTML 4.01 Transitional which supports everything found in XHTML 1.0 Strict also permitting the use of number of elements and attributes where they are judged.

XHTML 1.1

As mentioned before, XHTML version 1.1 is the latest W3C recommendation in XHTML programming. This versions is basically XHTML Strict with modifications here and there. For example, using a set of selected modules form a larger set defined in Modularization of XHTML. In addition to that, the disproval of certain features of HTML such as presentational elements and framesets even lang and anchor name attributes , which were still allow in XHTML 1.0 Strict has been removed . This version too requires a ruby markup support for East-Asian languages(CJK) and also the usage of CSS in presentation to operated functionally. Moreover, the XHTML 1.1 adds a concept of “strictly confirming” document which is a COMPLETE document containing elements that is derived in the modules required by XHTML 1.1

Other parts of the XHTML also includes:-

a) XHTML Voice - XHTML working together with XML Voice which supports voice and visual interactions
b) XHTML Basic - XHTML in special ‘lights’ version for more advanced and richer XHTML dialects. E.g handhelds,mobile phones
c) XHTML Mobile Phones - this OMA( Open Mobile Alliance) that targets specific hand phones.

As of now, the work and draft for XHTML 2.0 is still ongoing and its looking good. However no released date has been announced.

Motivation

Since our technology is constantly reaching higher levels, web contents now needs to be transferred to many other devices (such as mobile devices) and the normal desktop computer and with the current version of HTML, extra resources cannot be devoted to the extra complexity of HTML syntax. This is why a new version of HTML markup language is needed thus resulting in the creation of XHTML. However, the addition of the HTML-supporting browers have emerged with the Internet Explorer, the largest market share sooner than XHTML-support browsers.

Another objective of XHTML and XML markup languages was to fulfill users demands on parcers and user agents. With HTML, a number of user agents took the task of “correcting” errant document. On the other hand, XML requires user agents to give a ‘fatal error’ upon stumbling a distorted XML. This all means that the new XHTML browser supposedly neglects error recovery codes even though it still needs minor error detection checks. The suggestion that browsers post an error rather than carry out an attempt to repair malformed contents should help eliminate the issue of malformed contents.

A very practical feature of XHTML is that it inherits namespaces from XML Namespaces. With this feature, authors or groups of authors can now define their own XML elements, contents and attributes to merge with XHTML documents. This appears almost the same as the Semantic Flexibility of the ‘class’ attribute in the HTML element but less limitations. Some namespaces that can be mixed with XHTML such as Scalable Vector Graphics for markup of vector graphics, MathML for semantic math markup and RDFa for embedding RDF data.

Relationships to HTML

HTML technology is the forerunner to XHTML. Minor changes from HTML to the first version XHTML 1.0 are more focused to achieve conformance with XML. However, the major changes are important as there is a need to change the requirements that the documents must be well-formed and all the elements must be plainly closed as required in XML. In XML, elements and attribute names are case-sensitive, thus making the XHTML approach has been to define all tag names to be lowercase.

This contrasts with some earlier established traditions which began when HTML 2.0 was released when many used uppercase tags. In XHTML, quotes either single of double quotes must be enclosed with their own specified attribute values. This again contrasted with SGML and then HTML versions where numeric or Boolean attributes can dispense with quotes and are assumed to be strings. Elements are must be strictly closed including empty elements also known as singleton such commands as img and br.

HTML elements which are optional in content model will never appear in the DOM tree unless they are very specified. Example, an XHTML page MUST have a <.body> element and a table will not have a <.tbody> element unless the author specifies it.

Because XHTML and HTML are closely related technologies, and are sometimes they are said, documented and written about in parallel. Authors tend to conflate the two names using a parenthetical notation such as (X)HTML. This shows that the documentation and principles can be considered to apply generally to both standards.

Adoption

HTML 4.01 and XHTML 1.0 remains unfinished even though many years have passed since the Recommendation status of XHTML 1.0. Lets take Internet Explorer by Microsoft has had XML parsing abilities since the release of version 5.0 in 1999 but even up till now, Internet Explorer v7.0 still doesn’t support XHTML documents served as XML nor does the beta version of Internet Explorer 8. It only alters them correctly when are authored in agreement with the HTML compatibility guidelines. The implantation of XHTML support to the Internet Explorer would be difficult because of its compatible-oriented HTML parcer.

Inspite of that, most other browsers have already advanced support for all possible XHTML MIME type. Early implementations such as the Mozilla and Opera do no incrementally render XHTML as it is received over the network, giving a degraded user experience compared to that of regular HTML. Slowed effective rates of adoption have been caused by obstacles from browser vendors. Without broader browser support, XHTML documents will always be server as HTML documents thus subtle to some of the advantages of XML such as namespaces, parcing, and etc.

Overview

In the development a particular web, Cascading Style Sheets (CSS) is a style sheet used to describe a presentation of a specified document written in markup language. CSS is one of the most common applications needed for styling a web page written in HTML and XHTML and also documents including SVG and XUL. CSS enables the separation of document contents (written in certain markup language) from a document presentation (written in CSS) by helping readers to define colors , fonts, layout, and other aspects of documental presentation. This separation enhances content accessibility, provide more flexibility and control in the specification of presentation characteristics and reduce complexity and repetition in structural content. In addition to that, CSS enables the same markup page to be projected in different styles different rendering methods such as on screen, in print, voice, tactile devices an d Braille-based. In a cascade, priorities and weights are calculated and assigned to rules to determine which style rules applies if more than one rule matches with a particular element.

A style sheet consists of a number of rules, each set made up of one or a few selectors and a declaration block. Selectors are used to declare which element a style is to apply to. Elements may be grouped depending on how they are placed relative to each other in the markup code, or how they are implanted inside the Document Object Model thus making selectors able to apply to all elements of a specific type or only those elements which match a single attribute. Declaration-block however is made up of a list of semicolon-separated declarations in curly braces. Each declaration itself consists of a property, a colon (:), a value and a semi-colon (;).

Style sheet sources can be either attached as a separated document or embedded in the HTML document itself. Different styles can be used depending on the given output device. For example, the printed version can be quite different from the screen version. This allows the authors to be able to tailor the presentation appropriately for each medium. Multiple style sheets can be obtained thru import and alternative style sheets can be specified so that he user can choose between them.

History

Since the beginnings of SGML in the 1970s, Style sheets have existed whether in one form or another. Cascading Style Sheets (CSS) is created to provide style information for web documents.

HTML slowly came to cover a wider variety to meet the demands of web developers. Designers have more control over site appearance with this change but it is more complex to write and maintain the HTML. Users have less control over how web contents were displayed and the variations in web browser implementations made consistent site appearance difficult.

W3C’s www-style mailing lists were introduced to nine different style sheet languages to improve the capability of web presentations. Two of the nine proposals were chosen as the CSS foundation. The two proposals were Cascading HTML Style Sheets (CHSS) and Stream-based Style Sheet Proposal (SSP). The current CTO of Opera Software, H’kon Wium Lie proposed CHSS which is similar to the current CSS in October 1994. A browser called Argo which used its own style sheet language, SSP, was introduced by Bert Bos. Finally, the standard CSS was developed after Lie and Bos collaborated and worked together. The ‘H’ was removed from the name of the style sheets because these sheets are compatible with other markup language other than HTML.

The advantage of CSS unlike other style languages such as DSSSL or FOSI is that CSS allows a document’s style to be influenced by multiple style sheets.

Unlike existing style languages, CSS allowed a document's style to be influenced by multiple style sheets. One style sheet could inherit or "cascade" from another, permitting a mixture of stylistic preferences controlled equally by the site designer and user.

At the "Mosaic and the Web" conference in Chicago, Illinois in 1994 Håkon’s proposal was presented, and once again with Bert Bos in 1995.The World Wide Web Consortium was being established at around this time; the W3C took an interest in the development of CSS, and organized a workshop chaired by Steven Pemberton. This resulted in W3C adding work on CSS to the deliverables of the HTML editorial review board (ERB). Håkon and Bert were the primary technical staff on this aspect of the project, with additional members, including Thomas Reardon of Microsoft, participating as well. By the end of 1996, CSS was ready to become official, and the CSS level 1 Recommendation was published in December.

Development of HTML, CSS, and the DOM had all been taking place in one group, the HTML Editorial Review Board (ERB). Early in 1997, the ERB was split into three working groups: HTML Working group, chaired by Dan Connolly of W3C; DOM Working group, chaired by Lauren Wood of SoftQuad; and CSS Working group, chaired by Chris Lilley of W3C.

Issues that had not been tackled in CSS level 1 was addressed in CSS level 2 and work began in the 4th of November 1994. As of 2006 CSS level 3 was still under progress since being announced in 1998.

Difficulty with adoption

CSS level 1 specifications was completed in 1996 and IE 3 was released in that year featuring some limited support for CSS, however it would be more than 3 years before any web browser achieved near-full implementation of the specification. IE 5.0 for the Macintosh was the first browser to have better than 99 percent CSS level 1 support. Other browsers followed soon afterwards, many of them additionally implemented parts of CSS level 2, as of July 2006, no browser has fully implemented CSS level 2 with implementation levels varying.

Even though early browsers such as Internet Explorer 3 and 4, and Netscape 4.x had support for CSS, it was typically incomplete and afflicted with serious bugs. This was a serious obstacle for the adoption of CSS.

When later 'version 5' browsers began to offer a fairly full implementation of CSS, they were still incorrect in certain areas and were fraught with inconsistencies, bugs and other quirks. The proliferation of such CSS-related inconsistencies and even the variation in feature support has made it difficult for designers to achieve a consistent appearance across platforms. Some authors commonly resort to using some workarounds such as CSS hacks and CSS filters in order to obtain consistent results across web browsers and platforms.

Problems with browsers' patchy adoption of CSS along with errata in the original specification led the W3C to revise the CSS2 standard into CSS2.1, which may be regarded as something nearer to a working snapshot of current CSS support in HTML browsers. Some CSS2 properties which no browser had successfully implemented were dropped, and in a few cases, defined behaviours were changed to bring the standard into line with the predominant existing implementations. CSS2.1 became a Candidate Recommendation on February 25, 2004, but was pulled back to Working Draft status on June 13, 2005, and only returned to Candidate Recommendation status on July 19, 2007.

As of 2006 some older web servers are still configured to serve documents with the filename extension .css as mime type application/x-pointplus. This is because the Net-Scene company was selling PointPlus Maker to convert PowerPoint files into Compact Slide Show files (using the .css extension) and web servers were configured to signal to client browsers that these .css files were x-pointplus media type. Since the plugin was listed in the directory for Netscape Navigator 3.0, the popular Netscape Enterprise Server was distributed with this mapping pre-configured. When reading external style sheets some web browsers try to compensate for the misconfigured web servers by treating the PointPlus media type as a text/css media type instead, but some comply with the media type and will not render the external CSS file as a style sheet.

Variations

CSS has various levels and profiles. Each level of CSS builds upon the last, typically adding new features and typically denoted as CSS1, CSS2, and CSS3. Profiles are typically a subset of one or more levels of CSS built for a particular device or user interface. Currently there are profiles for mobile devices, printers, and television sets. Profiles should not be confused with media types which were added in CSS2.

The first CSS specification to become an official W3C Recommendation is CSS level 1, published in December 1996.Among its capabilities are support for:

* Font properties such as typeface and emphasis
* Color of text, backgrounds, and other elements
* Text attributes such as spacing between words, letters, and lines of text
* Alignment of text, images, tables and other elements
* Margin, border, padding, and positioning for most elements
* Unique identification and generic classification of groups of attributes

The W3C maintains the CSS1 Recommendation.

CSS level 2 was developed by the W3C and published as a Recommendation in May 1998. A superset of CSS1, CSS2 includes a number of new capabilities like absolute, relative, and fixed positioning of elements, the concept of media types, support for aural style sheets and bidirectional text, and new font properties such as shadows. The W3C maintains the CSS2 Recommendation.

CSS level 2 revision 1 or CSS 2.1 fixes errors in CSS2, removes poorly-supported features and adds already-implemented browser extensions to the specification. While it was a Candidate Recommendation for several months, on 15 June 2005 it was reverted to a working draft for further review.It was returned to Candidate Recommendation status on 19 July 2007.

CSS level 3 is currently under development.The W3C maintains a CSS3 progress report. As with the evolving XHTML specification, CSS3 is modularized and will consist of several separate Recommendations. An Introduction to CSS3 roadmap will be the starting point.

Overview

Javascript, a form of scripting language where it is most often used for client-side web development. Javascript was known to be the originating dialect of the ECMA script standard. It possesses 1st class functions coupled with weakly typed and prototype-based language. Despite the various influences, javascript was designed for easier usage by non programmers to work with. The language own be most commonly found in website usage. However, the language also enable scripting access to objects embedded in other applications such as Microsoft Gadgets. Apart from sharing the C syntax near similar name and naming conventions, Javascript is basically unrelated to the Java programming language. Due to the co-marketing deal between netscape and The Sun, the language was renamed from Livescript. The renaming of the language was and exchange for netscape bundling Sun's Java runtime with their browser as part of the co-marketing deal. Javascript to inherited various essential design principles from the Self programming language. Javascript doubles up as trademark of Sun Microsystems. Technology invented and implemented by Netscape Communications was done under license and this included current entites such as the Mozilla Foundations.

History

Brendan Eich of Netscape originally developed JavaScript under the name Mocha, later LiveScript before the final name of JavaScript. The name change to JavaScript from LiveScript is roughly together with Netscape adding support for Java technology in its Netscape Navigator web browser. December 1995, in Netscape browser version 2.0B3, JavaScript was introduced and deployed for the first time. The naming has caused confusion, giving the impression that the language is a spin-off of Java and has been characterized by many as a marketing ploy by Netscape to give JavaScript the cachet of what was then the hot new web-programming language.

Microsoft later named its dialect of the language Jscript to avoid trademark issues. It was first supported in internet explorer 3.0, released in August 1996 and included Y2K compliant date functions, unlike those based on java utilities dates in JavaScript at that time. The dialects are so similar that both the terms “JavaScript” and “Jscript” are often used interchangeably.

Netscape then submitted JavaScript to Ecma Internation for standardization resulting ECMAScript.