Eat your heart out, OpenOffice.

Microsoft Office 2010, due next year, will be available in a free version called Office 2010 Starter, the company's New Zealand chief technology officer Brett Roberts flagged over the weekend.

Like the no-cost Google Apps suite, Office 2010 Starter will be supported by advertising.

Although its name implies a trial version, Office 2010 Starter will have no time-limit.

But there’s a catch.

While the freebie Office 2010 Starter will have a similar interface as the full commercial version, including signature ribbon introduced with Office 2007, it offers only Word and Excel - and stripped down versions of the software at that.

If you want presentation graphics and database software as well, you’ll have to pay for the full commercial version of Office 2010 ... or download one of the proliferating number of free business software suites, which includes OpenOffice 3.0 - bankrolled in part by Google, IBM and others.

Another draw-back: Office 2010 Starter will only be available on new PCs, according to the Microsoft inhouse blog that broke the news.

Microsoft first began talking up an ad-funded version of Office as early as mid-2007.

But with Office on track to generate a staggering $US16 billion or so in sales this year - despite a 13% dip in its most recent quarter - Microsoft has been loath to mess with cash cow.

But now, it seems, the growing popularity of free and no-cost alternatives is getting to great to ignore.

Office in your browser
Its decision to release a free, ad-supported version of Office 2010 is the second radical move Microsoft has made with its new suite.

Its first was to announce a free, web version of Office 2010 that will see Word, Excel, PowerPoint, OneNote and other apps available in iterations that can run inside any web browser, allowing a user to view or edit files without Office 2010 being installed on a PC. This browser-based version of Office 2010 is currently being rolled out in an invitation-only trial.

The web version of Office 2010 is aimed squarely at Google Apps, which is available in both a free, ad-supported version and a more full-featured Premiere version that costs $US50 per user per year. New Zealand Post recently became the largest Australasian customer for Google Apps Premiere.