I wrote in this space last week that your company needs to stop using Microsoft’s Internet Explorer (IE) browser immediately.

Due to unsolvable security holes that have recently been demonstrated in IE, it looks like the free and soon-to-be-released Firefox browser, a project of the Mozilla Foundation, is becoming the new hot Web-surfing application of choice.

Will your company Web site be able to handle the hordes who are expected to switch to Firefox — or will your crucial corporate home page collapse in a cascade of error messages?

Cross-Browser Compatibility Is Important Once Again

Since its controversial bundling by Microsoft into Windows 98, IE has grown to rule the roost.

It boasted in June a 95% browser market share, according to Web traffic statistics from TheCounter.com (a service of Internet.com).

But you shouldn’t let IE’s current dominance lull you into testing your site’s compatibility only with that one browser.

Even one of Firefox’s harshest critics, Michael Horowitz, says the new browser will get big fast.

“I would think at least 10 percent” of Web surfers will be using Firefox within 12 months of its release, he said in a telephone interview.

Horowitz operates a Web site called ComputerGripes.com. In its pages, he complains about things he doesn’t like about Firefox — and almost every other computer program you can think of — but he reserves the lowest circle of Hell for corporate sites that don’t work when viewed with Firefox.

It’s usually good to have links to your site from other sites. But this is one page you don’t want to be mentioned on.

I found this out the hard way when a new version of an “expert tips” search engine I developed called WinFind aroused Horowitz’s ire.

WinFind’s search results, which looked perfect in IE, didn’t show up at all in Firefox. I was quickly able to fix this — a “hidden” style was incorrectly making everything hidden in Firefox — but would your own site be able to recover so easily?

A Few Major Gotchas To Watch Out For

You should immediately download the latest beta of Firefox — which at this writing is version 0.9.2, a stable build — and test your company’s Web pages in it.

Other important browsers to test include Mozilla, a precursor to Firefox; Opera; and Netscape, the grandaddy of browsers.

These programs differ in many respects, but you should focus on a few major problem areas to ensure your site will operate smoothly in all the above:

No ActiveX or VBScript

These proprietary Microsoft technologies have been criticized for years for their lack of a built-in, ground-up, bulletproof security model.

The latest computer takeovers by Russian hackers have made this weakness all too obvious. Browsers other than IE don’t run the flawed components.

Use Title Tags As Well As Alt Tags. 

Firefox and Mozilla faithfully follow the rules of the World Wide Web Consortium (W3C) and display Title tags, but not Alt tags, as tooltips.

IE for Windows displays both Alt and Title tags as tooltips. IE 5 for the Mac, however, behaves as Firefox and Mozilla do. Your site should use both Title and Alt tags properly. (See the “Alt” section in this description.)

Ignore the Microsoft Developer Network

Ben Goodger, the lead engineer of Firefox development for the Mozilla Foundation, explained in a telephone interview:

“You should not rely on MSDN as the only guide of what’s available or what should be used on the Web.”

This Microsoft site (and an associated magazine of the same name) is loaded with Web development techniques that — surprise, surprise — only work in IE.

Get Your Workarounds Ready

Switching your company’s default browser from IE to Firefox means you’ll face some small but potentially frustrating differences in behavior. Here are the most significant ones and the workarounds I suggest:

Windows Update Is The Worst

Microsoft’s Windows Update works only with IE. It’s coded so poorly that it doesn’t even display a warning message in plain text in other browsers to explain what’s going on.

“I’ve got to figure they’ve done that on purpose,” opines Horowitz. “A big company like Microsoft, with a site used as much as Windows Update, I can’t believe that’s an accident.”

Corporations that use centralized patch-management servers instead of Windows Update don’t need to worry.

Otherwise, you can run Windows Update normally in IE by selecting “Windows Update” from the operating system’s Start menu, which always works.

Forget About Remote-Scanning Services.

Web sites that offer to scan your PC using ActiveX controls — which includes TrendMicro’s HouseCall site and many other antivirus sites — won’t run in browsers other than IE.

To work around this, you can launch IE from the Start menu, as with the Windows Update example described above.

Use a Generic Add-In 

The easiest generalized fix for sites that don’t work well in Firefox is for you to install IE View for Windows.

This small (22 KB) extension adds a “View Page in Internet Explorer” option to Firefox’s context menus, so the choice is available at your fingertips. Over 190 other extensions are already offered, and more are on the way.

Conclusion

IE may seem to have a crushing lead, but sophisticated computer users are switching to competing browsers in greater numbers than overall statistics indicate.

At the Web sites that I myself operate for highly technical PC users — such as WindowsSecrets.com — almost 16% of the visitors are already using some version of Mozilla or Firefox.

IE makes up only 78% of these visitors’ browsers. And that’s down from 81% as recently as January 2004.

That makes this the perfect time for your company to put cross-browser compatibility on the top of your to-do list.

The “preview release” of Firefox will go live as soon as early August, according to Chris Hoffman, the Mozilla Foundation’s director of engineering.

The target for a full 1.0 release, including numerous international translations, is September 15. That “gold” version will install perfectly over Firefox 0.9, Hoffman says.

It could be a lot cheaper for you to make some coding changes in your HTML than it would be for you to watch a significant percentage of your customers flee to other sites.