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Making Globally Compatible Webpages

Browser Differences

Updated June 18/98.
Netscape Dynamic HTML not supported.
Items Netscape IExplorer Opera WebEx HTML
4.0.x 3.0.x 4.0.x 3.0.x 3.x 1.1h 3.2 2.0
Underlines, strikeouts Yes Yes Yes Yes Yes Yes Yes No
Animated GIFs Yes Yes Yes Yes Yes Yes No No
Fixed backgrounds No No Yes Yes No No No No
Low res image proxy Yes Yes No No No No No No
Client-side imagemaps
 Yes Yes Yes Yes No No Yes No
Multiple columns, spacers Yes Yes No No No No No No
BODY ALINK Colour Yes Yes Sort of No No No Yes No
Cascading Style Sheets (CSS) All No Most Some No No No1 No
Page left/top margins Yes No Yes Yes No No No No
Font support
Sizes/Colours Yes Yes Yes Yes Yes Yes Yes2 No
Typefaces Yes Yes3 Yes Yes Yes No No No
Form fields font any monospaced Arial, size 2 any Courier any monospaced
Table support
ALIGN=center Yes TR,TD Yes TR,TD Yes Yes Yes Yes
Background colour Yes Yes Yes Yes Yes No No No
Background image Yes No Yes Yes No No No No
Border colour One No Yes; shades No No No No
Programming support
JavaScript (Netscape) 1.2 1.1 No4 No4 1.0 No No No
Java (Sun) 1.1 1.0 1.15 1.05 No No 1.0 No
ActiveX (Microsoft)6 Yes No Yes Yes No No No No
VBScript (Microsoft) No No 2.0 1.0 No No No No
Frames support
General support Yes Yes Yes Yes Yes No No No
Borderless frames Yes Yes Yes Yes Yes No No No
Floating frames Yes No Yes Yes No No No No
Inline multimedia
Embedded sounds Yes; EMBED Yes; BGSOUND No No No No
Plugins (RealAudio,
Shockwave, etc.)		 Yes Yes Most Most Some No No No
Items Netscape IExplorer Opera WebEx HTML
  1. HTML 3.2 can hide any code within <STYLE> tags, but cannot run it. This is to ensure backwards compatibility when the CSS1 specification is fully drafted.
  2. The W3C does not fully endorse the use of FONT SIZE or FONT COLOR due to its problems with accessibility options for the colour-blind and visually-impaired, but it does have superscript, subscript, big and small font tags.
  3. Netscape's FONT FACE attribute will not display font names within tables if called outside of them.
  4. Microsoft uses its own proprietary version of JavaScript, called JScript, which is essentially a clone of version 1.0 (for IE3) and 1.2 (for IE4) minus several functions.
  5. Microsoft uses its own proprietary version of Java. Compatibility problems have been detected.
  6. ActiveX technology only works on Win32 platforms.

Browser Deep Backgrounds

* NETSCAPE NAVIGATOR

Recommended versions: 3.04, 4.06
Netscape was developed by NCSA Mosaic alumnus Marc Andreessen and Jim Clark in 1994. With the introduction of innovative browser-specific tags such as CENTER and FONT COLOR with version 1.1, Netscape is still the clear choice among Internet users, and its HTML specifications are the most widely seen and supported, even more so than the "official" standards developed by the W3C. Of note, form field borders appear more pronounced in Netscape. Also, headlines (HR) appear much darker in version 4 than in 3.

With Netscape 2.0 came the first web scripting language fully written within a webpage, called JavaScript. Netscape has, with version 4, the capability to display HTML blocks in X, Y and Z (for layers) coordinates anywhere on a page, as well as offering dynamic HTML support (animation) and increased Java access security. A beta of version 4.5 and the source code of the upcoming 5.0 is also available. Netscape currently holds 67% of the browser market and is available for MacOS, OS/2, all versions of Windows plus a dozen XWindows platforms. The standalone Navigator plus the groupware Communicator is now free.

* MICROSOFT INTERNET EXPLORER

Recommended version: 4.01a
MSIE was developed in 1995 as a hasty redress of licensed Mosaic code. Version 3.0 proved to be more decent than its predecessor, offering some Netscape-specific tags as well as its own, such as IMG DYNSRC (for inline multimedia), the Recreational Software Advisory Council's META rating tag, ActiveX multimedia support and its own scripting language, VBScript.

Overall, IE mimics Netscape on page presentation, but IE is more slack on erroneous HTML code. The left margin is a few pixels thicker. The unsightly vertical scrollbar never leaves the window, regardless of page length. Form fields are displayed incredibly small, with erroneous lengths. Scrollbars on drop-down lists may obscure the text inside. To top it off, IE ignores </P> tags, sometimes ignores space characters between objects, and omits extra linespaces following tables, lists, etc.

Version 4.0, for Win32 and Macintosh, claims to rewrite the user interface, for Internet integration and offer HTML 4.0 support. Too bad it crashes all the time. Microsoft currently holds 33% of the market and is available at no cost for Windows 3.1, 95, NT and Mac.

* OPERA

Recommended version: 3.21
First written in Norway in 1994, Opera is an extremely well-coded browser, using less than 2MB of HD space and yet offering creature comforts such as a multi-document interface, keyboard navigation and handicap, frames and cookies support. It almost parallels Netscape 3 in features (and includes some of its own, like zoom-in), but at a fraction of the overhead. Runnable on as little as a 386SX, Opera has a small, but loyal following.

However, only 477 colours can be displayed, and there is no Java and only partial JavaScript support. There are also some viewing quirks, such as improper text-wrapping around images, interlaced transparent GIFs appearing with borders, and lists (in OL, DL or UL tags) appearing double-spaced. Both vertical and horizontal scrollbars also do not disappear, regardless of page size. Opera is shareware, and is available for all versions of Windows with MacOS, Unix, BeOS, Amiga and Psion versions under development.

* IBM WEBEXPLORER

Recommended version: 1.1h
WebEx was developed in 1995 by IBM for its OS/2 Warp Connect Internet package. WebExplorer includes many tags from Netscape 1.1, and proves very efficient in OS/2's multi-threaded environment. WebEx also allows users to drag and drop images and pages directly onto the desktop. IBM still offers WebExplorer for free. The latest version is 1.1h, which supports tables.

* LYNX

Recommended version: 2.7.2
Lynx, written by the University of Kansas, is the one and only text non-WYSIWYG web browser. Even tables and font attributes are not supported; headers, italics, bolding and hyperlinks are often signified by colour. Images and imagemaps, should the IMG ALT attribute be omitted, are rendered as "[IMAGE]" or similar statements. Navigation is through the keyboard. However, because Lynx does so little page formatting, it is extremely fast and requires low processing power. It is ideal for slow modems, dial-up shell (non-SLIP/PPP) connections, and text-to-speech software used by visually-impaired net surfers. Universities, freenets and libraries often use Lynx.

Sadly, in the age of the graphical user interface, many web authors neglect to take Lynx into account, and therefore many pages are virtually useless to Lynx users. Version 2.7 now supports persistent cookies. Lynx is available free for Unix, OS/2, DOS, Win32, VMS, Amiga and even Atari, and a Mac version is in the works.

* SGML DTD for HTML

The official document type definition for HyperText Markup Language is managed by the World Wide Web Consortium (W3C). Mosaic, the first browser ever, was developed in 1993 by the NCSA to completely support the official HTML standards of its time.

HTML 2.0 (1994) was the first true written standard, and closely followed by many browsers. HTML 3.0 and its browser Arena were drafted in 1995 but soon abandoned. It should be noted that HTML 3.0 and its features, such as figures, are NOT supported or endorsed at all.

HTML 3.2, codenamed "Wilbur", is the latest revision (1996), incorporating some of the work in 3.0 as well as offering CGI-free imagemaps, Java applet support and backwards compatibility with cascading style sheets (CSS). The most interesting change in HTML 3.2 is that it does not support the &quot; tag for quotations; coders are advised to use its ISO numeric code or the " character. The official browser of HTML 3.2 is the W3C's Amaya.

BEYOND HTML: CSS, COUGAR AND XML

Current plans are to develop HTML 4.0 "Cougar", the new HTML definition to include full support of stylesheets. The current CSS Level 1 standards allow fine control over paragraph margins, indentation, font attributes, line spacing and text-highlighting. Level 2 proposes aural stylesheets (for text dictation programs), printer formatting, and other improvements. Cougar promises many other new features, such as enhanced forms, with disabled buttons, grouped buttons, tooltips and keyboard shortcuts. A standard for embedding objects and scripts will be established. There will be more robust character sets, for other languages and math and iconic symbols. There will be tables that are scrollable with fixed headers and tables that break across pages for printing. And not only will frames be finally supported, they can be embedded within a document.

In the future, the W3C hopes to complete its draft of XML, Extensible Markup Language. The successor to HTML, XML aims to offer the flexibility of SGML (Standard Generalized Markup Language) with the user-friendliness of HTML. XML is by definition a metalanguage, meaning it is fully customizable and one can produce their own tags. Hyperlinking and making stylesheets are also much easier.

W3C generally frowns on many of the tags Netscape and Microsoft has developed, as the two browser giants have produced many compatibility problems with each other and other browsers with their "illegitimate" code spec.

Different Environments

The major curse - and blessing - with producing webpages is its global coverage. Your webpage will be viewed by different browsers, computer and Internet connection speeds, monitors and video cards, and operating systems. The reader may be visually impaired, or colour-blind. And this is all not considering human factors such as language proficiency. A page that looks great on Netscape 4.0 on your Pentium's hard drive with a 16 million colour 17" screen hooked up can easily be illegible on a 486 laptop with 16 colours connected on a 14.4 modem.

Before publishing a webpage, test it on a variety of browsers and systems. Keep your pages and images small in file size.

Make sure your colours are of sufficient contrast. If 256 colour support is important, you can use the designated "safe" colour codes: 00, 33, 66, 99, CC and FF. Combinations of these hexadecimal colours will display without any colour correction on 256 colour screens. Try to use colour codes instead of names when possible.

In general, try to stick to the HTML 3.2 and 2.0 standards. Backwards compatibility is a very important issue. However, if you use proprietary or very new tags to spice up your layout, such as frames and stylesheets, give your less-endowed users the option of an alternative, "watered-down" version of your site, or keep enhancements transparent.

For more information, refer to the Best Viewed with Any Browser site.

"Real Life? I've played that game. The plot stinks but the graphics are awesome."
-- "Havoc"'s character in an online, multiplayer game

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