ALL YOU NEED TO KNOW ABOUT EB DESIGN. CHAPTER 1

 Chapter 1. HTML, XHTML, and the World Wide Web 

Though it began as a military experiment and spent its adolescence as a sandbox for academics and eccentrics, in less than a decade the worldwide network of computer networks -- also known as the Internet — has matured into a highly diversified, financially important community of computer users and information vendors. From the boardroom to your living room, you can bump into Internet users of nearly any and all nationalities, of any and all persuasions, from serious to frivolous individuals, from businesses to nonprofit organizations, and from born-again Christian evangelists to pornographers.

In many ways, the Web — the open community of hypertext-enabled document servers and readers on the Internet — is responsible for the meteoric rise in the network's popularity. You, too, can become a valued member by contributing: writing HTML and XHTML documents and then making them available to web surfers worldwide.

Let's climb up the Internet family tree to gain some deeper insight into its magnificence, not only as an exercise of curiosity, but to help us better understand just who and what it is we are dealing with when we go online. 

1.1 The Internet

Although popular media accounts are often confused and confusing, the concept of the Internet really is rather simple: it's a worldwide collection of computer networks — a network of networks — sharing digital information via a common set of networking and software protocols.

Networks are not new to computers. What makes the Internet unique is its worldwide collection of digital telecommunication links that share a common set of computer-network technologies, protocols, and applications. Whether you run Microsoft Windows XP, Linux, Mac OS X, or even the now ancient Windows 3.1, when connected to the Internet, computers all speak the same networking language and use functionally identical programs, so you can exchange information — even multimedia pictures and sound — with someone next door or across the planet.

The common and now quite familiar programs people use to communicate and distribute their work over the Internet have also found their way into private and semi-private networks. These so-called intranets and extranets use the same software, applications, and networking protocols as the Internet. But unlike the Internet, intranets are private networks, with access restricted to members of the institution. Likewise, extranets restrict access but use the Internet to provide services to members.

The Internet, on the other hand, seemingly has no restrictions. Anyone with a computer and the right networking software and connection can "get on the Net" and begin exchanging words, sounds, and pictures with others around the world, day or night: no membership required. And that's precisely what is confusing about the Internet.

Like an oriental bazaar, the Internet is not well organized, there are few content guides, and it can take a lot of time and technical expertise to tap its full potential. That's because . . .

1.1.1 In the Beginning

The Internet began in the late 1960s as an experiment in the design of robust computer networks. The goal was to construct a network of computers that could withstand the loss of several machines without compromising the ability of the remaining ones to communicate. Funding came from the U.S. Department of Defense, which had a vested interest in building information networks that could withstand nuclear attack.

The resulting network was a marvelous technical success, but it was limited in size and scope. For the most part, only defense contractors and academic institutions could gain access to what was then known as the ARPAnet (Advanced Research Projects Agency Network of the Department of Defense).

With the advent of high-speed modems for digital communication over common phone lines, some individuals and organizations not directly tied to the main digital pipelines began connecting and taking advantage of the network's advanced and global communications. Nonetheless, it wasn't until the last decade (around 1993, actually) that the Internet really took off.

Several crucial events led to the meteoric rise in popularity of the Internet. First, in the early 1990s, businesses and individuals eager to take advantage of the ease and power of global digital communications finally pressured the largest computer networks on the mostly U.S. government-funded Internet to open their systems for nearly unrestricted traffic. (Remember, the network wasn't designed to route information based on content — meaning that commercial messages went through university computers that at the time forbade such activity.)

True to their academic traditions of free exchange and sharing, many of the original Internet members continued to make substantial portions of their electronic collections of documents and software available to the newcomers — free for the taking! Global communications, a wealth of free software and information: who could resist?

Well, frankly, the Internet was a tough row to hoe back then. Getting connected and using the various software tools, if they were even available for their computers, presented an insurmountable technology barrier for most people. And most available information was plain-vanilla ASCII text about academic subjects, not the neatly packaged fare that attracts users to services such as America Online. The Internet was just too disorganized, and, outside of the government and academia, few people had the knowledge or interest to learn how to use the arcane software or the time to spend rummaging through documents looking for ones of interest.

1.1.2 HTML and the Web

It took another spark to light the Internet rocket. At about the same time the Internet opened up for business, some physicists at CERN, the European Particle Physics Laboratory, released an authoring language and distribution system they developed for creating and sharing multimedia-enabled, integrated electronic documents over the Internet. And so was born Hypertext Markup Language (HTML), browser software, and the Web. No longer did authors have to distribute their work as fragmented collections of pictures, sounds, and text. HTML unified those elements. Moreover, the Web's systems enabled hypertext linking, whereby documents automatically reference other documents located anywhere around the world: less rummaging, more productive time online.

Lift-off happened when some bright students and faculty at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, Urbana-Champaign wrote a web browser called Mosaic. Although designed primarily for viewing HTML documents, the software also had built-in tools to access the much more prolific resources on the Internet, such as FTP archives of software and Gopher-organized collections of documents.

With versions based on easy-to-use graphical user interfaces familiar to most computer owners, Mosaic became an instant success. It, like most Internet software, was available on the Net for free. Millions of users snatched up copies and began surfing the Internet for "cool web pages."

1.1.3 Golden Threads

There you have the history of the Internet and the Web in a nutshell: from rags to riches in just a few short years. The Internet has spawned an entirely new medium for worldwide information exchange and commerce. For instance, when the marketers caught on to the fact that they could cheaply produce and deliver eye-catching, wow-and-whizbang commercials and product catalogs to those millions of web surfers around the world, there was no stopping the stampede of blue suede shoes. Even the key developers of Mosaic and related web server technologies sensed potential riches. They left NCSA and made their fortunes with Netscape Communications by producing commercial web browsers and server software. That was until the sleeping giant Microsoft awoke. But that's another story . . .

Business users and marketing opportunities have helped invigorate the Internet and fuel its phenomenal growth. Internet-based commerce has become Very Big Business and is expected to approach US$150 billion annually by 2005.

For some, particularly us Internet old-timers, business and marketing have also trashed the medium. In many ways, the Web has become a vast strip mall and an annoying advertising medium. Believe it or not, once upon a time, Internet users adhered to commonly held (but not formally codified) rules of netiquette that prohibited such things as "spamming" special-interest newsgroups with messages unrelated to the topic at hand or sending unsolicited email.

Nonetheless, the power of HTML and network distribution of information goes well beyond marketing and monetary rewards: serious informational pursuits also benefit. Publications, complete with images and other media like executable software, can get to their intended audiences in the blink of an eye, instead of the months traditionally required for printing and mail delivery. Education takes a great leap forward when students gain access to the great libraries of the world. And at times of leisure, the interactive capabilities of HTML links can reinvigorate our otherwise television-numbed minds.

 

1.2 Talking the Internet Talk

Every computer connected to the Internet (even a beat-up old Apple II) has a unique address: a number whose format is defined by the Internet protocol (IP), the standard that defines how messages are passed from one machine to another on the Net. An IP address is made up of four numbers, each less than 256, joined together by periods, such as 192.12.248.73 or 131.58.97.254.

While computers deal only with numbers, people prefer names. For this reason, each computer on the Internet also has a name bestowed upon it by its owner. There are several million machines on the Net, so it would be very difficult to come up with that many unique names, let alone keep track of them all. Recall, though, that the Internet is a network of networks. It is divided into groups known as domains, which are further divided into one or more subdomains. So, while you might choose a very common name for your computer, it becomes unique when you append, like surnames, all of the machine's domain names as a period-separated suffix, creating a fully qualified domain name.

This naming stuff is easier than it sounds. For example, the fully qualified domain name www.oreilly.com translates to a machine named "www" that's part of the domain known as "oreilly," which, in turn, is part of the commercial (com) branch of the Internet. Other branches of the Internet include educational institutions (edu), nonprofit organizations (org), the U.S. government (gov), and Internet service providers (net). Computers and networks outside the United States may have two-letter abbreviations at the end of their names: for example, "ca" for Canada, "jp" for Japan, and "uk" for the United Kingdom.

Special computers, known as name servers, keep tables of machine names and their associated unique numerical IP addresses and translate one into the other for us and for our machines. Domain names must be registered and paid for through any one of the now many for-profit registrars.^[1] Once it is registered, the owner of the unique domain name broadcasts it and its address to other domain name servers around the world. Each domain and subdomain has an associated name server, so ultimately every machine is known uniquely by both a name and an IP address.

^[1] At one time, a single nonprofit organization known as InterNIC handled that function. Now ICANN.org coordinates U.S. government-related name servers, but other organizations or individuals must work through a for-profit company to register their unique domain names.

1.2.1 Clients, Servers, and Browsers

The Internet connects two kinds of computers: servers, which serve up documents, and clients, which retrieve and display documents for us humans. Things that happen on the server machine are said to be on the server side, while activities on the client machine occur on the client side.

To access and display HTML documents, we run programs called browsers on our client computers. These browser clients talk to special web servers over the Internet to access and retrieve electronic documents.

Several web browsers are available (most for free), each offering a different set of features. For example, browsers like Lynx run on character-based clients and display documents only as text. Others run on clients with graphical displays and render documents using proportional fonts and color graphics on a 1024 x 768, 24-bit-per-pixel display. Others still — Netscape Navigator, Microsoft's Internet Explorer, and Opera, to name the leading few — have special features that allow you to retrieve and display a variety of electronic documents over the Internet, including audio and video multimedia.

1.2.2 The Flow of Information

All web activity begins on the client side, when a user starts his or her browser. The browser begins by loading a home page document, either from local storage or from a server over some network, such as the Internet, a corporate intranet, or a town extranet. In these latter cases, the client browser first consults a domain name system (DNS) server to translate the home page document server's name, such as www.oreilly.com, into an IP address, before sending a request to that server over the Internet. This request (and the server's reply) is formatted according to the dictates of the Hypertext Transfer Protocol (HTTP) standard.

A server spends most of its time listening to the network, waiting for document requests with the server's unique address stamped on them. Upon receipt of a request, the server verifies that the requesting browser is allowed to retrieve documents from the server and, if so, checks for the requested document. If found, the server sends (downloads) the document to the browser. The server usually logs the request, the client computer's name, the document requested, and the time.

Back on the browser, the document arrives. If it's a plain-vanilla ASCII text file, most browsers display it in a common, plain-vanilla way. Document directories, too, are treated like plain documents, although most graphical browsers display folder icons that the user can select with the mouse to download the contents of subdirectories.

Browsers also retrieve context files from a server. Unless assisted by a helper program or specially enabled by plug-in software or applets, which display an image or video file or play an audio file, the browser usually stores downloaded binary files directly on a local disk for later use.

For the most part, however, the browser retrieves a special document that appears to be a plain text file but that contains both text and special markup codes called tags. The browser processes these HTML or XHTML documents, formatting the text based on the tags and downloading special accessory files, such as images.

The user reads the document, selects a hyperlink to another document, and the entire process starts over.

1.2.3 Beneath the Web

We should point out again that browsers and HTTP servers need not be part of the Web to function. In fact, you never need to be connected to the Internet or to any network, for that matter, to write documents and operate a browser. You can load and display locally stored documents and accessory files directly on your browser. Many organizations take advantage of this capability by distributing catalogues and product manuals, for instance, on a much less expensive, but much more interactively useful, CD-ROM, rather than via traditional print on paper.

Isolating web documents is good for the author, too, since it gives you the opportunity to finish, in the editorial sense of the word, a document collection for later distribution. Diligent authors work locally to write and proof their documents before releasing them for general distribution, thereby sparing readers the agonies of broken image files and bogus hyperlinks.^[2]

^[2] Vigorous testing of HTML documents once they are made available on the Web is, of course, also highly recommended and necessary to rid them of various linking bugs.

Organizations, too, can be connected to the Internet but also maintain private webs and document collections for distribution to clients on their local networks, or intranets. In fact, private webs are fast becoming the technology of choice for the paperless offices we've heard so much about during these last few years. With HTML and XHTML document collections, businesses can maintain personnel databases complete with employee photographs and online handbooks, collections of blueprints, parts, assembly manuals, and so on — all readily and easily accessed electronically by authorized users and displayed on a local computer.

1.2.4 Standards Organizations

Like many popular technologies, HTML started out as an informal specification used by only a few people. As more and more authors began to use the language, it became obvious that more formal means were needed to define and manage — i.e., to standardize — the language's features, making it easier for everyone to create and share documents.

1.2.4.1 The World Wide Web Consortium

The World Wide Web Consortium (W3C) was formed with the charter to define the standards for HTML and, later, XHTML. Members are responsible for drafting, circulating for review, and modifying the standard based on cross-Internet feedback to best meet the needs of the many.

Beyond HTML and XHTML, the W3C has the broader responsibility of standardizing any technology related to the Web; they manage the HTTP, Cascading Style Sheets (CSS), and Extensible Markup Language (XML) standards, as well as related standards for document addressing on the Web. They also solicit draft standards for extensions to existing web technologies.

If you want to track HTML, XML, XHTML, CSS, and other exciting web development and related technologies, contact the W3C at http://www.w3.org.

Also, several Internet newsgroups are devoted to the Web, each a part of the comp.infosystems.www hierarchy. These include comp.infosystems.www.authoring.html and comp.infosystems.www.authoring.images.

1.2.4.2 The Internet Engineering Task Force

Even broader in reach than W3C, the Internet Engineering Task Force (IETF) is responsible for defining and managing every aspect of Internet technology. The Web is just one small area under the purview of the IETF.

The IETF defines all of the technology of the Internet via official documents known as Requests for Comments, or RFCs. Individually numbered for easy reference, each RFC addresses a specific Internet technology — everything from the syntax of domain names and the allocation of IP addresses to the format of electronic mail messages.

To learn more about the IETF and follow the progress of various RFCs as they are circulated for review and revision, visit the IETF home page, http://www.ietf.org. 

 1.3 HTML and XHTML: What They Are

 

HTML and XHTML are document-layout and hyperlink-specification languages. They define the syntax and placement of special, embedded directions that aren't displayed by the browser but tell it how to display the contents of the document, including text, images, and other support media. The languages also tell you how to make a document interactive through special hypertext links, which connect your document with other documents — on either your computer or someone else's — as well as with other Internet resources.

You've certainly heard of HTML, and perhaps XHTML too, but did you know that they are just two of many other markup languages? Indeed, HTML is the black sheep in the family of document markup languages. HTML was based on SGML, the Standard Generalized Markup Language. The powers-that-be created SGML with the intent that it be the one and only markup metalanguage from which all other document markup elements would be created. Everything from hieroglyphics to HTML can be defined using SGML, negating any need for any other markup language.

The problem with SGML is that it is so broad and all-encompassing that mere mortals cannot use it. Using SGML effectively requires very expensive and complex tools that are completely beyond the scope of regular people who just want to bang out an HTML document in their spare time. As a result, HTML adheres to some, but not all, SGML standards,^[3] eliminating many of the more esoteric features so that it is readily useable and used.

^[3] The HTML DTD in Appendix D uses a subset of SGML to define the HTML 4.01 standard.

Besides the fact that SGML is unwieldy and not well suited to describing the very popular HTML in a useful way, there was also a growing need to define other HTML-like markup languages to handle different network documents. Accordingly, the W3C defined the Extensible Markup Language (XML). Like SGML, XML is a separate formal markup metalanguage that uses select features of SGML to define markup languages. It eliminates many features of SGML that aren't applicable to languages like HTML and simplifies other SGML elements in order to make them easier to use and understand.

However, HTML Version 4.01 is not XML-compliant. Hence, the W3C offers XHTML, a reformulation of HTML that is compliant with XML. XHTML attempts to support every last nit and feature of HTML 4.01 using the more rigid rules of XML. It generally succeeds, but it has enough differences to make life difficult for the standards-conscious HTML author. 

1.4 HTML and XHTML: What They Aren't

Despite all their new, multimedia-enabling page-layout features, and the hot technologies that give life to HTML/XHTML documents over the Internet, it is also important to understand the languages' limitations. They are not word-processing tools, desktop-publishing solutions, or even programming languages. Their fundamental purpose is to define the structure and appearance of documents and document families so that they may be delivered quickly and easily to a user over a network for rendering on a variety of display devices. Jack of all trades, but master of none, so to speak.

1.4.1 Content Versus Appearance

HTML and its progeny, XHTML, provide many different ways to let you define the appearance of your documents: font specifications, line breaks, and multicolumn text are all features of the language. Of course, appearance is important, since it can have either detrimental or beneficial effects on how users access and use the information in your documents.

Nonetheless, we believe that content is paramount; appearance is secondary, particularly since it is less predictable, given the variety of browser graphics and text-formatting capabilities. In fact, HTML and XHTML contain many ways for structuring your document content without regard to the final appearance: section headers, structured lists, paragraphs, rules, titles, and embedded images are all defined by the standard languages without regard for how these elements might be rendered by a browser. Consider, for example, a browser for the blind, wherein graphics on the page come with audio descriptions and alternative rules for navigation. The HTML/XHTML standards define such a thing: content over visual presentation.

If you treat HTML or XHTML as a document-generation tool, you will be sorely disappointed in your ability to format your document in a specific way. There is simply not enough capability built into the languages to allow you to create the kinds of documents you might whip up with tools like FrameMaker or Microsoft Word. Attempts to subvert the supplied structuring elements to achieve specific formatting tricks seldom work across all browsers. In short, don't waste your time trying to force HTML and XHTML to do things they were never designed to do.

Instead, use HTML and XHTML in the manner for which they were designed: indicating the structure of a document so that the browser can then render its content appropriately. HTML and XHTML are rife with tags that let you indicate the semantics of your document content, something that is missing from tools like FrameMaker and Word. Create your documents using these tags and you'll be happier, your documents will look better, and your readers will benefit immensely.

1.5 Standards and Extensions

The basic syntax and semantics of HTML are defined in the HTML standard, now in its final version, 4.01. HTML matured quickly, in barely a decade. At one time, a new version would appear before you had a chance to finish reading an earlier edition of this book. Today, HTML has stopped evolving. As far as the W3C is concerned, XHTML has taken over. Now the wait is for browser manufacturers to implement the standards.

The XHTML standard currently is Version 1.0. Fortunately, XHTML Version 1.0 is, for the most part, a reconstitution of HTML Version 4.0.1. There are some differences, which we explore in Chapter 16. The popular browsers continue to support HTML documents, so there is no cause to stampede to XHTML. Do, however, start walking in that direction: a newer XHTML version, 1.1, is under consideration at the W3C, and browser developers are slowly but surely dropping nonstandard HTML features from their products.

Obviously, browser developers rely upon standards to have their software properly format and display common HTML and XHTML documents. Authors use the standards to make sure they are writing effective, correct documents that get displayed properly by the browsers.

However, standards are not always explicit; manufacturers have some leeway in how their browsers might display an element. And to complicate matters, commercial forces have pushed developers to add into their browsers nonstandard extensions meant to improve the language.

Confused? Don't be: in this book, we explore in detail the syntax, semantics, and idioms of the HTML Version 4.01 and XHTML Version 1.0 languages, along with the many important extensions that are supported in the latest versions of the most popular browsers.

1.5.1 Nonstandard Extensions

It doesn't take an advanced degree in The Obvious to know that distinction draws attention. So, too, with browsers. Extra whizbang features can give the edge in the otherwise standardized browser market. That can be a nightmare for authors. A lot of people want you to use the latest and greatest gimmick or even useful HTML/XHTML extension. But it's not part of the standard, and not all browsers support it. In fact, on occasion, the popular browsers support different ways of doing the same thing.

1.5.2 Extensions: Pro and Con

Every software vendor adheres to the technological standards; it's embarrassing to be incompatible, and your competitors will take every opportunity to remind buyers of your product's failure to comply, no matter how arcane or useless that standard might be. At the same time, vendors seek to make their products different from and better than the competition's offerings. Netscape's and Internet Explorer's extensions to standard HTML are perfect examples of these market pressures.

Many document authors feel safe using these extended browsers' nonstandard extensions because of their combined and commanding share of users. For better or worse, extensions to HTML in prominent browsers become part of the street version of the language, much like English slang creeping into the vocabulary of most Frenchmen, despite the best efforts of the Académie Française.

Fortunately, with HTML Version 4.0, the W3C standards caught up with the browser manufacturers. In fact, the tables turned somewhat. The many extensions to HTML that originally appeared as extensions in Netscape Navigator and Microsoft Internet Explorer are now part of the HTML 4 and XHTML 1.0 standards, and there are other parts of the new standard that are not yet features of the popular browsers.

1.5.3 Avoiding Extensions

In general, we urge you to resist using extensions unless you have a compelling and overriding reason to do so. By using them, particularly in key portions of your documents, you run the risk of losing a substantial portion of your potential readership. Sure, the Internet Explorer community is large enough to make this point moot now, but even so, you are excluding from your pages millions of people who use Netscape.

Of course, there are varying degrees of dependency on extensions. If you use some of the horizontal rule extensions, for example, most other browsers will ignore the extended attributes and render a conventional horizontal rule. On the other hand, reliance upon a number of font-size changes and text-alignment extensions to control your document's appearance will make your document look terrible on many alternative browsers. It might not even display at all on browsers that don't support the extensions.

We admit that it is disingenuous of us to decry the use of extensions while presenting complete descriptions of their use. In keeping with the general philosophy of the Internet, we'll err on the side of handing out rope and guns to all interested parties while hoping you have enough smarts to keep from hanging yourself or shooting yourself in the foot.

Our advice still holds, though: use an extension only where it is necessary or very advantageous, and do so with the understanding that you are disenfranchising a portion of your audience. To that end, you might even consider providing separate, standards-based versions of your documents to accommodate users of other browsers.

1.5.4 Extensions Through Modules

The upcoming XHTML Version 1.1 provides a mechanism for extending the language in a standard way: XML modules. In fact, XHTML 1.1 is comprised of modules itself.

XHTML modules divide the HTML language into discrete document types, each defining features and functions that are parts of the language. There are separate modules for XHTML forms, text, scripting, tables, and so on — all the nondeprecated elements of XHTML 1.0.

The advantage of modules is extensibility. In addition to using the markup features from the XHTML modules normally included in the standard, the new language lets you easily blend other XML modules into your documents, extending their features and capabilities in a standard way. For instance, the W3C has defined a MathML module that provides explicit markup elements for mathematical equations that you could use in your next XHTML-based math thesis.

Modules, let alone the XHTML Version 1.1 language, are experimental and are not well supported by the popular browsers. Accordingly, we don't recommend that you use XHTML modules just yet. For now, the subject is beyond the scope of this book. Consult the W3C web site for more details.

1.6 Tools for the Web Designer

While you can use the barest of barebones text editors to create HTML and XHTML documents, most authors have a bit more elaborate toolbox of software utilities than a simple word processor. You also need a browser, so you can test and refine your work. Beyond the essentials are some specialized software tools for developing and preparing HTML documents and accessory multimedia files.

1.6.1 Essentials

At the very least, you'll need an editor, a browser to check your work, and, ideally, a connection to the Internet.

1.6.1.1 Word processor or WYSIWYG editor?

Some authors use the word-processing capabilities of their specialized HTML/XHTML editing software. Some use the WYSIWYG (what-you-see-is-what-you-get) composition tools that come with their browsers or the latest versions of the popular word processors. Others, such as ourselves, prefer to compose their work on a general word processor and later insert the markup tags and their attributes. Still others include markup as they compose.

We think the stepwise approach — compose, then mark up — is the better way. We find that once we've defined and written the document's content, it's much easier to make a second pass to judiciously and effectively add the HTML/XHTML tags to format the text. Otherwise, the markup can obscure the content. Note, too, that unless specially trained (if they can be), spell-checkers and thesauruses typically choke on markup tags and their various parameters. You can spend what seems to be a lifetime clicking the Ignore button on all those otherwise valid markup tags when syntax- or spell-checking a document.

When and how you embed markup tags into your document dictates the tools you need. We recommend that you use a good word processor, which comes with more and better writing tools than simple text editors or the browser-based markup-language editors. You'll find, for instance, that an outliner, spell-checker, and thesaurus will best help you craft the document's flow and content, disregarding for the moment its look. The latest word processors encode your documents with HTML, too, but don't expect miracles. Except for boilerplate documents, you will probably need to nurse those automated HTML documents to full health. (Not to mention put them on a diet when you see how long the generated HTML is.) And it'll be a while before you'll see XHTML-specific markup tools in the popular word processors.

Another word of caution about automated composition tools: they typically change or insert content (e.g., replacing relative hyperlinks with full ones) and arrange your document in ways that will annoy you. Annoying, in particular, since they rarely give you the opportunity to do things your own way.

Become fluent in native HTML/XHTML. Be prepared to reverse some of the things a composition tool will do to your documents. And make sure you can wrest your document away from the tool so you can make it do your bidding.

1.6.1.2 Browser software

Obviously, you should view your newly composed documents and test their functionality before you release them for use by others. For serious authors, particularly those looking to push their documents beyond the HTML/XHTML standards, we recommend that you have several browsers, perhaps with versions running on different computers, just to be sure one's delightful display isn't another's nightmare.

The currently popular — and therefore most important — browsers are Netscape Navigator (the browser portion of Netscape Communicator) and Microsoft Internet Explorer. Download the latest versions from their web sites.

By the way, Netscape Communicator includes a fine HTML WYSIWYG editor called Composer.

1.6.2 An Extended Toolkit

If you're serious about creating documents, you'll soon find there are all sorts of nifty tools that make life easier. The list of freeware, shareware, and commercial products grows daily, so it's not very useful to provide a list here. This is, in fact, another good reason to frequent the various newsgroups and web sites that keep updated lists of HTML and XHTML resources on the Web. If you are really dedicated to writing in HTML and XHTML, you will visit those sites, and you will visit them regularly to keep abreast of the language, tools, and trends.