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Once the web site is complete the next important task is to publish it on the web. As a single web site can contain lots of HTML documents rich in multimedia content, hyperlinks and other real time resources it is quite difficult to manage the whole structure and publish each document on the World Wide Web perfectly. Thus in order to make the web publishing easy different companies has come up with a number of web publishing softwares which offer a large number of options and tools. Below are some of the popular web publishing tools:

Netscape Navigator Gold: It offers a visual editing environment that is same as a web page so that the user can edit and publish his HTML documents without getting confused. Netscape Navigator Gold includes a number of formatting tools, menu designers and text editors. Right from the visual appearance to directory structure management, the Navigator Gold is able to handle everything smoothly.

Backstage Desktop Studio: This one is developed by Macromedia and consists of a complete suite of web publishing tools to assemble and manage end-to-end HTML documents. The Backstage Desktop Studio specializes in Web authoring. It features WYSIWYG (What You See Is What You Get) interface which makes it easy to design the web page. Apart from this the desktop studio offers dynamic options for site management.

Page Mill and Site Mill: Both Page Mill and Site Mill are the excellent tools for web page design and publishing created by Adobe. Most of the features of these two applications are similar in nature and thus one can use any of them in place of each other.

The Site Mill is a perfect choice for managing and editing the HTML documents. It records the whole structure of the web site and checks each hyperlink for its reliability and functionality and the remaining content whether in the form of text or images, and displays all the errors.

The Page Mill can be used in two different modes, i.e. Browse Mode and Edit Mode. The Browse Mode is the default mode of the application and it allows you to view your page in exactly the same manner it will look on the web. In the Edit Mode you can make the necessary changes to your web site. Page Mill supports a variety of operations such as cut, copy, paste, RTF (Rich Text Format) support, image editing, hyperlink management, site map management, image maps management, web site navigation management, style sheets handling, form, frames, tables and much more.

Apart from all these applications there are other tools also which provides awesome options for editing and managing the HTML documents. Some of them are Adobe GoLive, HotDog, HotDog Pro, HoTMetal, HoTMetal Pro etc. All of them are equipped with the WYSIWYG feature. However there are some differences among them with respect to the Operating System needed, supported file extensions, processing speed etc. One can make use of any one or more depending upon his/her needs.

Once the web pages has been designed it is very important that they are verified and tested completely before going live on the World Wide Web. Verification here means to check the HTML documents for a large number of errors and testing refer to the checking the reliability, functionality and compatibility of the web pages. During verification the HTML documents are generally examined with respect to their layout, typographic errors, grammatical mistakes and so on. In testing phase all the scripts, functions, applets, embedded tools, CSS (Cascading Style Sheets), DHTML effects etc. are checked.

If you are dealing with a complex web site containing a large number of HTML documents then verifying and testing each and every resource manually can be cumbersome. Therefore, in order to ensure high level of accuracy and to save time a large number of sophisticated computer programs can be used. Below are some popular verification services which can be used to test the web pages:

• Doctor HTML: This is a verification service which is used to analyze the contents of a web page in detail. It can be used for checking different aspects of the HTML documents such as spelling, images, the structure of the document, tables, hyperlinks, forms and much more. It should be noted that Doctor HTML is not a software which can be downloaded and installed in the computer, rather it is a web service (a Common Gateway Interface, CGI script) for which one has to subscribe in order to get his/her web site verified.

• Weblint: Just like Doctor HTML, Weblint is also a web based service which is used to test and verify the HTML documents. It can be used to check the basic structure of the website, to check for the unknown elements and attributes, tag context, overlapped tags, illegally nested tags, images, hyperlinks, obsolete tags etc.

• WebTechs: It is also a web based service which can be used to check whether a particular HTML document or web site conforms to the predefined standards or not.

• Some of the other web site verification services are Slovenian HTMLchek, U.S.M.A (United States Military Academy’s verification service), Harbinger and URL-Minder.

In case you have to verify a small number of HTML documents then it is recommended that apart from using the online verification services you check the web pages yourself also so that the chances of mistakes are minimized. While performing a manual check makes sure that there are no spelling errors, grammatical errors and formatting errors. The navigation structure of the web site should be checked for consistency, all the DHTML effects should be tested in order to see if they are working in the way they were supposed to and the tables should be checked for their alignment. Besides this, all the images, hyperlinks, background scripts and forms should also be checked thoroughly.

Site verification and testing is a continuous and dynamic process. As the web standards change from time to time the web sites are also updated frequently and retested according to the new standards and procedures.

One of the most basic elements of the HTML document is the frame. A frame is basically a device which allows you to open two or more pages in the same window. Mostly the frame concept is used in cases where you wish to split the window. As is the case with many websites, the left hand side is like a navigation strip, a separate page which is a tabulated list of the topics with the relevant links, while the right hand side shows the content related to those topics.

Reading this you might be misled into believing that there are two pages in the window but there are in fact three pages. One tends to forget there is one page which is holding both the pages. This page is called the ‘container’ page, which contains both the pages. All we need to do is open this page and both the other pages automatically open in this page. The format of this page is similar to any other pages.

The HTML frames concept is generally regarded as quite complicated and very hard for new users to grasp. There is an on-going debate among the champions and critics of frames. The critics feel that frames are associated with a few problems, which is why they wish new users to avoid them.

One popular opinion is that they interfere with the basic concept of the web. The web is ideally supposed to be a group of pages, each page with a separate URL and these pages are simply interlinked. On the other hand, frames allow number of pages to have the same URL and when one bookmarks any of these pages, they end up with the URL of the container page.

A second problem with the frameset pages is that they are not browser friendly. Although not a problem now but a bunch of earlier browsers could not access the framed pages. Even now, when such pages are opened on devices other than computers, like palmtops or phones, they do not allow the browser to resize them which makes page viewing cumbersome. Similar to the resizing issue is the printing problem. Browsers find it hard to print such pages and the prints are never satisfactory. There is also the general overall feel that such pages are hard to code especially be novice coders.

Arguably the biggest problem with frames is that they are not search engine friendly. Even search engines like Google do not go through the content of the internal pages and only read the content of the container page.

The champions of frames on the other hand feel the benefits they create are worth a few hassles and they mostly cite the example of inline frames. Inline frames are special frames which circumvent most of the aforementioned problems. Inline frames are also called floating frames. The basic difference between these and the conventional frames is that these pages open in your container page like images or tables would. The coding for these is also quite easy and they present no obvious problems.

As discussed earlier, a cache proxy server is the one which stores the HTML documents and other web resources in its own storage space so that they can be delivered to the client without any delay.

Types of Caching

Caching can be passive as well as active. In passive caching the cache proxy server stores the web resources each time the client requests it. First of all, the cache server looks into its own database to check whether the requested resource is there or not. If it founds the desired data then there is no need to contact the web server and the data is delivered to the client instantly. If the proxy server doesn’t get the requested resource in its own database then it retrieves it from the relevant location on the internet and saves it for the future reference.

In active caching the cache proxy server stores and updates its database during its idle time. Whenever the cache server is not accessed by the clients for a set duration it learns the most frequently used resources, downloads them via internet and finally saves them in its cache for future reference. During the process of active caching the proxy server also checks for any updates regarding those resources which are already there in its database.

Challenges in Caching Process

No doubt that the cache servers incredibly reduce the latency periods and facilitate smooth data transactions, but the file caching process faces great challenges. This is not at all an easy task because the resources that have been saved in the cache server are static in nature but the web is highly dynamic and unpredictable. Sometimes a web page remains same for a long period and suddenly changes and sometimes changes are made every day. In case of real time applications such as sports and news web sites the updates are being done every second. So the cache server gets really into trouble while keeping all its records up to date so that the client doesn’t miss any single bit of information.

A large number of heuristic methods have been evolved till now and are being improved continuously in order to make the file caching more reliable and efficient. Sophisticated technologies are being implemented so that the cache server can keep its database up to date by updating the web documents and deleting the stale/expired records.

Load Balancing the Caching work

The caching can be done by implementing more than one cache proxy server and operating the whole array simultaneously. This benefits the organization in the way that the work load of caching can be shared among all the proxy servers. Thus, the caching can be done more effectively and speedily. This also increases the storage space to be used for storing HTML documents and other web applications. The whole array of cache servers can also be configured in such a way that if one cache server fails, then the remaining ones provide fault tolerance just like the Redundant Array of Inexpensive Disks (RAID).

In today’s world the internet is growing at the speed of a jet. Day by day websites are being improved in terms of interactivity, entertainment, multimedia, graphics and animations. HTML documents now do not refer to the static pages which were used as the source of information only. In fact, the web is being used as the all in one entertainer for every age group.

Web sites based on gaming, animations, 3D graphics etc. are designed to provide the children the whole package of fun and excitement on their fingertips. Customers can look at the product features and virtually use the products before they actually buy it by real time simulation on World Wide Web. These miracles are possible only because of VRML language.

VRML, short for Virtual Reality Modeling Language is a language impeccably designed to facilitate hi-end 3 dimensional real time simulations on the internet. Initially, the SGML and its derivative HTML, both were designed to support two dimensional structures. But with the evolution of VRML, the internet standards have been redesigned in order to full utilize the 3D powers of the web. VRML uses various types of virtual reality objects and virtual worlds which uses three dimensional paradigms for different purposes. These placements of these objects with respect to each other can be defined using the VRML co-ordinate system. Once the positioning has been done, you can define the behavior of different elements of your virtual world.

VRML can be used to beautifully design the HTML documents. This language invokes life in the static web pages. You can do a number of tasks via VRML such as:

• Adding motion to an object
• Creating a virtual world
• 3D simulation of products
• Improving graphics
• Inserting event oriented tasks
• Controlling the behavior of various elements of the virtual world
• Embedding and controlling animations in HTML documents
• Inserting real time games in web sites

How to view VRML worlds?

To view a VRML world we need a VRML browser. A VRML browser is just like the other web browser but it has got additional features which support fascinating world of VRML. VRML browser reads a VRML file and displays the complex geometry, animations and lightning effects as a 3D world. If the 3D world allows navigation, you can examine the different objects of VRML world and navigate through it in an exciting way. VRML browser can be installed as a standalone software application or it can be embedded in the existing web browser as a plug-in.

The best VRML browser

There are a number of VRML browsers available in the market but no one is best. Every VRML browser has got its own set of benefits and constraints. While choosing a VRML browser one should keep in mind the cost, features, objective of using the VRML browser, extra features, hardware acceleration, scripting and overall performance. If you are using the VRML browser as a plug-in, you should also keep in mind that for which browser you need VRML before you select a particular one because for different web browsers different types of VRML plug-ins are developed.

Since its evolution in 1994, the most impressive web developer language VRML has been through a lots of modifications and upgrades. In the year 1997, VRML was upgraded for the first time and its name was changed from VRML94 to VRML97 (which is also known as VRML2 or VRML 2.0). This upgraded version of the web language became an ISO standard and was used to design home pages and sites offering 3D chat facilities.

As the web graphics and vectors began to improve, a lot of alternate languages emerged in order to provide better options for virtual 3D modeling and stood in the competition. The various alternatives to the traditional VRML language are:

A) COLLADA: It stands for COLLAborative Design Activity for developing interchangeable file format for 3D applications. This language defines an open standard XML schema which lays down the standards for exchanging the digital files among a number of graphic software applications.

COLLADA documents use XML files having a .dae (digital asset exchange) extension. This language was originally produced to facilitate transfer of digital data from one digital content creation tool to another DCC. This language is used by a number of popular applications such as Maya, 3D Studio Max, Google Earth etc.

B) U3D: Short for Universal 3D, U3D represents the compressed file format for 3D data. It was developed to get a universal standard for exchanging all types of 3D data.

C) X3D: It is a successor of VRML which was developed to enhance the VRML capabilities. X3D features various extensions to VRML such as Humanoid Animation, NURBS, GoeVRML etc. X3D defines a large number of extensions which are used for various purposes. Some of the popular X3D extensions are X3D Core, X3D Interchange, X3D CAD, X3D Geospatial and X3D Immersive.

D) 3DMLW: It is short for 3D Markup Language for Web. This is an XML based standard file format which is used for representing both three dimensional as well as two dimensional interactive content on the World Wide Web. 3DMLW is an open source engine and is licensed under GPL (General Public License).

In order to view and ripe the amazing benefits of 3DMLW, a 3DMLW plug-in or a 3DMLW standalone web browser has to be installed on the PC. The plug-in renders the 3D and 2D effects using the OpenGL (Open Graphics Library) standard. Thus it can be used under cross language, cross platform environments.

3DMLW separated the 2D and 3D objects and uses a text file format based on the XML 1.0 standard.

All the different 3D applications and graphic standards have their own abilities and disabilities. Therefore, one should keep in mind the objective of using these applications, the features of the applications, the cost and scalability factor while choosing one of them. You can also use more than one application and standard simultaneously to have a larger pool of exciting features as most of them supports cross platform functionality as well as backward compatibility.

Since its evolution, the HTML (Hyper Text Markup Language) has been revised and upgraded a number of times in order to make the World Wide Web a better place to live virtually. HTML is a derivative of SGML (Standard Generalized Markup Language), but its major flaw is that it is not extensible. Thus HTML is not appropriate for deployment under a network environment.

So, the World Wide Web Consortium (popularly known as W3C) decided to develop a new breed of extensible language and came up with XML, which stands for eXtensible Markup Language. Web developers use XML to dynamically describe the information stored on a web page. Though XML, the new generation web pages describes themselves which is helpful to gain good rankings in search engine listings and help the developers to write codes for custom search tools.

• XML shall be straightforwardly usable over the Internet.
• XML shall support a wide variety of applications.
• XML shall be compatible with SGML.
• It shall be easy to write programs that process XML documents.
• The number of optional features shall be kept to the absolute minimum, ideally zero.
• XML documents shall be human-legible and reasonably clear.
• The XML design should be prepared quickly.
• The design of XML shall be formal and concise.
• XML documents shall be easy to create.
• Terseness in XML markup is of minimal importance.

(Source: http://www.w3.org/TR/REC-xml/)

XML is referred as a Metalanguage which describes other languages. It is called so because XML allows the web developers to create documents which describes themselves to their reader. Though the XML tags look like the HTML ones, the main difference between the two is that the HTML documents do not tell the web browser how to display the web page. On the other hand, the XML documents are downloaded by the web browser along with a style sheet or Document Type definition (DTD) which guides the web browser on how to display the web page.

In its raw form, an XML document looks like the HTML and SGML documents, but all are functionally different. The main difference between the HTML and XML coding is that the XML tags are very rigid. For example; the HTML language has tags which have a closing and which don’t have a closing section. But in XML either all the tags must exist in pair or announce to the reader that a closing tag is not present.

For example: in HTML you can use <BR> tag without having to close it, but in XML you have to use it as <BR>…</BR> or simply as <BR/> which announces that there is no closing tag for BR.

Another prominent difference between the two languages is that the XML requires all the tag attribute values to be enclosed within quotation marks. For example:

<font color=red>……</font>, this is wrong in XML. It should be like <font color=”red”>…….</font>

HTML can be classified into two categories namely SGML based HTML (traditional) pitted against XML based HTML (also called XHTML) and the second one being a strict versus transitional versus frameset. In this article, the former has been described in detail.

One notable difference between the traditional version and XHTML is the technical distinction between the two of them. However, Inspite of all the modifications being done, the root element name “HTML” has been kept the same. The area which requires loads of effort is the one where the limitations of XML start showing in comparison to the more complex SGML inspite of the W3C intended HTML 4.01 being identical to XHTML 1.0. Due to the similarity quotient between HTML and XHTML, they are documented in parallel at many times.

The difference between an XHTML 1.0 document and an HTML 4.01 document is mostly syntactic in each of the corresponding DTDs except for the different opening declarations applicable for the document. There are many shortcuts which XHTML does not allow but HTML allows because of the underlying syntax. Be it elements with optional opening or closing tags, empty elements not having an end tag, all these are examples of the shortcuts that a user can take advantage of in HTML. HTML requires all elements to have an opening tag or a closing tag.

After contemplating on the whole process, the developers of XHTML have also come out with a shortcut. The opening and closing of an HTML tag has to be done within the same tag but a slash (/) can be added before the closing of the tag. For demonstration of the concept, let us take this example: <avi/>, where “<” is the opening tag and “>” the closing tag, “avi” is a fictitious HTML tag and as mentioned above, the slash (/) comes before the tag is closed.

To properly understand the minute differences between HTML and XHTML, the tips listed below need to be kept in mind:

. XHTML makes use of XML’s built in language defining functionality attribute. The language for an element should be specified with a lang attribute rather than the XHTML attribute.
. The XML namespace has to be removed as HTML does not have a provision for namespaces.
. The document type declaration has to be changed from XHTML 1.0 to HTML 4.01.
. The empty-element syntax of an XML has to be developed into a style empty element of an HTML.

A technically well constructed XHTML document will always follow all the syntax requirements of XML. The structure of a document is thoroughly described by the content of XHTML and legitimate documents will religiously follow its specified data.

To migrate easily between HTML and XHTML, several conventions have been recommended by the W3C and by meticulously following these guidelines, a user will be able to easily interpret the document as HTML or XHTML. The XHTML 1.0 documents that have been made compatible in this way are permitted by the W3C to be served either as HTML or as XHTML.