Browser Compatibility Issues

This page sets out some of the issues connected with writing these pages in such a way as to allow them to be viewed with as may browsers as possible.

Such an ambition is all very well, but the biggest obstacle to achieving this goal is the sheer number of internet browsers in use. At first glance, it may seem that there only two in widespread use - Microsoft Internet Explorer and Netscape Navigator.

Let's see which one (if either) you're using.

Each of what we might term the Big Two browsers has a number of versions, and within each version there are often several sub-versions. Furthermore, there may be subtle differences between what is nominally the same version running under different operating systems. Features available in the 32 bit Windows version may not be present in the Mackintosh version, or vice versa.

It's impossible to know what the inner thoughts of a web browser designer (or, more accurately, a team of web browser designers) are, but two influences seem to be at work here. First, a genuine attempt to advance the capabilities of browsers. Without that sort of drive, web browsers would display only text, and probably (for PC users) in a DOS window at that. Indeed, without the desire to make computers smaller and better, a computer probably still cost several millions of the currency unit of your choice, fill an entire building, and communicate with the outside world only by the use of a glorified electric typewriter.

The second influence is the desire for one team of designers to be able to say "My Browser Is Better Than Your Browser". There is some excuse for this - after all, being better than the competition is a powerful selling point, and the desire to be one up on the competition is a large part of most technological advances. Unfortunately, it causes certain problems to the beleaguered web page author. As I mentioned before, various features in one browser aren't present in another. By and large, if a feature is introduced in one browser, its rival(s) will incorporate the feature in their next version - but not always.

Clearly, there's little chance that any but the plainest of plain vanilla web pages will be accessible to every sub version of every version of every browser in the world. Start using JavaScript, or VBScript, on a web page, and the chances that someone, somewhere, won't be able to read the page increase dramatically. Not only are there several different versions of JavaScript, there are small but significant differences in their implementation between the Big Two. Furthermore, those browsers that are capable of scripting also offer the user the option of turning scripting off.

Coping With Browser Incompatibilty

The approach that I've adopted here is to separate my pages into two categories - content pages and display pages.

The content pages are the ones that are intended to be read, and are (for the main part) written using only HTML, without any JavaScript or VBScript. They are intended to be accessible to the most basic of browsers, and contain the information I consider most relevant. Where I have given in to temptation and included scripting on a page, then I've either designed the scripts to not be critical to the correct display of the page, or included a simplified version of the page elesewhere.

There is a risk that some the d may not be entirely compatible with some of the very early browsers. In an attempt to minimise that risk, I've started to use the text-only browser Lynx, as a "lowest common denominator" test of readability. Sometimes the layout isn't very pretty, but at least the pages are readable.

The display pages aren't intended to be read - they're basically containers for the content pages. If the content pages are like pictures or certificates hung on your wall, then the display pages are like their frames. The display pages aren't essential to browsing this site, they just make it look prettier (well, that's what I think, anyway) and give me a chance to play around with formatting and scripting.

That being said, I've been keeping an eye on what software/hardware configurations are most popular amongst visitors to this site, and it does seem to be worthwhile to offer the choice of Frames/JavaScript content. For what it's worth, the figures as of the end of March 1999 were:

Most Common Operating System: Windows 95 (81%)

Runners up: Windows NT (9%), Mackintosh (4%), Windows 3.1 (2%), UNIX, Linux etc(2%)

Most Common Javascript: Version 1.2 (84%)

Runners up: Version 1 / 1.1 (14%), None(2%)

Most Common Screen Resolution: 800 x 600 (72%)

Most Common Colour Depth: 16 Million (24 bit) (67%)

Most Common Browser: Internet Explorer 4 (67%)