KEY POINTS:
You have to tip your hat to Microsoft - not only has it kept selling its Windows operating system with the majority of new computers bought worldwide, Microsoft Office is the best-selling productivity suite.
I sometimes spend eight hours or more a day tapping away in Microsoft Word, and even if you're a casual PC user, you'll likely know what menu to click on to print a document, how to justify a paragraph or get a word count on what you've just written.
Only too aware of the powerful double-act Windows and Office represent, Microsoft's rivals are ramping up efforts to dismantle Office's hegemony. That was clear last week, when internet giant Google announced US technology consulting heavyweight Capgemini would offer computer support services to large companies wanting to run Google Apps, a web-based Office rival.
Google Apps Premiere Edition consists of a word processor, spreadsheet maker, email with 10GB online storage, calendar and the Google Talk instant messaging and internet telephony client. Google will allow these services to be delivered from a central portal adapted to include the company's branding. GAPE will cost US$50 a year for each user.
I've been using the free Google Docs online word processor for some time to create documents when I don't have my computer with me. It's not as sophisticated as Word, but is simple to use and fast to load. It has more functionality than the Wordpad program that comes supplied with Windows.
I've also been organising my life around Gmail since the service started and paid to raise my storage limit to 9GB. I'm pretty much already in the GAPE world and have been so long enough to see the potential for large companies seeking to deliver a basic set of productivity and communications tools to a large number of people.
The combination becomes even more potent when Google evolves the online services to make it easier to work on them when you're not connected to the internet, but quickly update everything as soon as you connect again. It is potent because Google is aiming at the average office worker, who needs basic word processing and spreadsheet tools and access to email. A lot of those people use Word and Excel.
Microsoft, which undertook a sizeable overhaul of its flagship software suite with Office 2007, met the Capgemini news by posing 10 questions designed to pick holes in Google Apps.
"Google's Apps only work if an enterprise has no power users, employees are always online, enterprises haven't built custom Office apps - doesn't this equal a very small percentage of global information workers today?" Microsoft asked.
It raises a valid point, but the software giant is unsettled by Google's willingness to stray into Microsoft's core market - large companies buying licences for hundreds or thousands of copies of Office.
And once people start using Google Apps at work and get to know it, they're more likely to sign up for the free consumer suite on offer for work at home.
Added to the mix is the open source Openoffice.org movement, which consists of a rival, free set of productivity tools modelled on Microsoft Office.
IBM revealed it will throw its development might behind Open Office, initially incorporating some of the code used in its Lotus Notes email platform into Open Office. Among the numerous other Office rivals are ZoHo and Apple's iWorks.
All of that points to an intensifying battle by software makers to supply the programs that computer users spend most time using - word processor and email client.
Microsoft Office won't go out of fashion soon but that viable, cheaper alternatives have emerged that could for the first time dent the huge share of the productivity software market Microsoft holds.
