With desktop market share still ranging from miniscule to small, relatively speaking, there's an enormous interest in Microsoft alternatives such as Linux and Mac OS X.

Most of us have been conditioned for so long that the Microsoft "platform" is essential that we scarcely pause to think about alternatives. But as long as we can perform our essential tasks - print that report, send that e-mail - does the operating system really matter?

Today, most applications offer a browser-based interface and most of the popular browsers - Internet Explorer, FireFox, Opera - can be had free of charge in versions that run on non-Microsoft platforms. And running Outlook Web Access, for example, on an Apple Mac using either Microsoft's own Internet Explorer 5.0 or Apple's Safari browser is 99% the same as running it on a Windows machine. With a few minor adjustments - such as holding the control key while clicking to download an attachment - you are on your way.

Basic e-mail - most people's key application - essentially is operating system independent already. Those who require synchronization with central servers, such as Exchange, have a bit more to deal with - but more about that later.

In terms of importance, "office" functions usually are right up there on the list alongside e-mail. While most of us are married to "Office 2003," we typically don't need to be. The document formats used for Word and Excel can be manipulated by "freeware" office suites such as OpenOffice and NeoOffice/J that run on Linux and OS X. If you just can't live without Microsoft Office you can get Office: Mac 2004 that will give you highly compatible versions of Word, Excel and PowerPoint.

In June 2005, Microsoft announced that the next version of Office - Office 12 - would introduce native XML file formats for Word (docx), Excel (xlx) and PowerPoint (pptx) that would - are you sitting down? - be "open" and even "documented." Thus, any current incompatibilities are likely to disappear before too long.

But what about Access and Outlook on non-Microsoft platforms? There, things get more complicated. While there are quite a few good quality relational database offerings out there, if Access is a "must" then having a Windows operating system is a "must," as well.