Microsoft today has added a free, 30-day trial version of its Office for Mac software to coincide with this year's Macworld Expo, taking place later this week in San Francisco.

Since the release of Office for Mac 2011 in October of last year, the only way to give the product a spin was to visit a retailer with a copy installed, or to purchase it. Now users can download the 600MB trial from Microsoft's Office site, which contains full versions of all its applications. When the trial expires, users can then upgrade to either the Home and Student, or Home and Business versions.

Microsoft has been less forthcoming about the successes of its Mac Office suite, saying only that it's running on about three-fourths of all Macs on the market. That's compared to the PC version, which Microsoft CEO Steve Ballmer recently announced was selling at one copy per second. However, in a company blog post, Pat Fox, Office for Mac's senior director of product management, said the 2011 version of the software had "gone past" the company's internal sales milestones.

Office for Mac continues to be offered as a bundle of applications, unlike its PC counterpart, which has long been offered as individual applications that can be purchased and used without the others. In an interview last year with CNET, Kurt DelBene, the president of Microsoft's Office division, said the company views the value of the Mac Office suite as both the sum of its parts and as individual applications--something worth keeping an eye on, if Microsoft decides to offer a downloadable version of Office through Apple's recently launched Mac App Store.