Microsoft has advised Mac users to switch to newer browsers

If you've got a Macintosh computer running Mac OS X and you like to use Microsoft's Internet Explorer for browsing the web, then I'm afraid I've got some bad news for you.

The Mac version of IE has not been updated for over two years, apart from the regular stream of security patches that are the lot of every Microsoft program, and now the company has announced that it is being dropped.

It won't be supported, security issues won't be fixed and it won't be available for download from the Mactopia website. Game over for the IE-using Mac population, unless they are willing to run an unpatched browser and take their chances with the hackers.

This might seem to be a rather minor and somewhat abstruse issue, of importance to relatively few people. After all, I'm writing this on my Apple laptop and a quick check reveals that I haven't run IE once, even though it's nearly a year old.

I do occasionally use IE on my Windows desktop, since I'm neither a Mac zealot nor anti-Microsoft, and I know that both of my children use IE as well as the open source Firefox browser when they are looking at web pages, so it's not that I've turned away from it completely.

But on the Mac I've got Safari, Apple's browser, as well as Firefox, and three browsers just seems rather excessive.

So far I haven't come across a website that requires me to use IE, not even when I'm downloading updates to Microsoft Office for the Mac - I told you I wasn't ideologically opposed to Microsoft software - but I've no doubt I will, and when it happens I'll be stuck.

Closed standards

Last June a survey of UK websites by the consultancy SciVisum found that one in 10 of the sites they looked at limited non-Microsoft browsers. Some of those, like the Odeon cinema site, have since improved, but many remain wholly or partially inaccessible to those who don't use IE.

The main reason is that many Microsoft-based sites use a technology called ActiveX to embed active content in their web pages. ActiveX is essentially a Windows-only way of doing the sorts of things that a standards-based website would use Java or Javascript for, and it is not supported by the standard releases of Firefox.

If the company really wants to show that it has changed its approach to business it could take the radical step of placing the source code for the Mac version of IE into the hands of users End nears for IE for Macs

You can get an ActiveX plugin for Firefox, though it is still only being tested for compatibility with the latest Firefox release, 1.5, and the page you get it from warns you of the serious security implications of installing it.

This is hardly an ideal solution, and of course if Microsoft decides to change the ActiveX specification, which it may do at any time since they own it, then all the third-party software will stop working.

That's the danger of building an open information system on closed standards. Microsoft's behaviour over IE on the Mac is simply the latest example, and highlights a number of serious issues with the closed, proprietary approach to software development that characterises most of the industry today.

Microsoft has worked hard for many years to lock users in to IE. It has extended its capabilities with completely novel technologies like ActiveX controls; it has integrated it so closely into the Windows operating system that competition authorities around the world have been forced to intervene; and it has ensured that IE works better with websites running on Microsoft's own web server, IIS, than others do.

The result has been a large number of companies who have developed a web presence that either requires or certainly benefits from the use of IE. In one famous example, victims of Hurricane Katrina who wanted to apply for public support could only do so if they used IE as their browser.

Yet now, for reasons which it is not obliged to divulge, it can cut that support from users of a competing operating system and leave them potentially locked out of sites.

Not only that, but because IE is closed source the community, in the form of competent programmers, has no way of taking on the cancelled project and keeping it going.

Free the code

Microsoft is currently in trouble with the European authorities over its failure to give competitors access to details of its server software after a ruling in March 2004. It may be fined up to 2m euros (£1.36m; $2.4m) a day if it does not comply.

If the company really wants to show that it has changed its approach to business it could take the radical step of placing the source code for the Mac version of IE into the hands of users.

It would be too much to hope for the code to be made public domain and given away without any copyright restrictions, but it could at least get its highly-paid legal team to come up with a reasonably permissive licence that would let coders get their hands on the last supported version and keep it going.

Not only would this confound many of their critics, who see the decision to drop IE support as a retaliation against the new-found popularity of the Mac with the iPod generation, but it would give it a massive credibility boost with the free/open source community.

A few months ago Microsoft simplified and improved the licences under which it made the source code of some products available for inspection. Now it could go a step further, and actually let us work with its code and keep this useful product alive.

I might even consider running an open source IE build on my laptop, if I knew that I wouldn't have to rely on Microsoft's support for a minority operating system to get bug fixes done.