Where is the next Office for the Mac?

Microsoft is behind the schedule it used for the last several iterations, and has not breathed a word about its Mac intentions. In fact, the blog kept by the California-based development team that works on Office for Mac hasn't been updated since Aug. 5, 2013, more than seven months ago.

That's what those in the trade call stealth mode.

The last time Microsoft launched a new Office for OS X was October 2010, when it rolled out Office for Mac 2011. Prior to that, Microsoft issued upgrades in January 2008 (Office for Mac 2008), May 2004 (Office for Mac 2004) and November 2001 (Office v. X).

The average spread between Office for Mac editions -- going back as far as Office v. X -- has been 1,088 days. But as of Thursday, it had been 1,213 days since the launch of Office for Mac 2011.

Historically, Microsoft has hewn to a three-year development cycle for both Office on the Mac and the far-more-popular Office suite for Windows, with a new version of the former following the newest of the latter by several months at a minimum.

Office for Mac 2011, for instance, followed Office 2010 on Windows by 134 days, or just over four months. Office for Mac 2008, however, came 351 days, or nearly a year, after the debut of its Windows sibling, Office 2007. But even the longer lag time of the latter has now been exceeded: Office 2013 for Windows launched Jan. 29, 2013, 13 months ago.

The development team responsible for Office on the Mac, dubbed Macintosh Business Unit (MacBU), requires the lag time to incorporate changes that other engineering groups made to the Windows predecessor. The Windows and OS X Office development teams don't work in tandem, but in sequence, with Windows taking the lead and OS X following.

What's odd is Microsoft's silence about the next Office for the Mac. The last cycle -- for Office for Mac 2011 -- the company was comparatively loquacious, announcing its intentions to craft the suite about 14 months before shipping the software, and it gave semi-regular updates on its MacBU blog.

News of the next Office for Mac? Nothing.

There's no chance that Microsoft will pull Office for the Mac from its portfolio: The company has touted Office 365, the rent-not-own subscription plans for both consumers and businesses, as providing up to five licenses for either Windows or OS X editions of the suites' desktop applications. To dump the Mac suite, even though its sales are Lilliputian in comparison to that for Windows, would be an embarrassment at least, and seen as a betrayal by those who committed to subscriptions rather than buy traditional "perpetual" licenses.

Still, Microsoft looks out over a different landscape than 40 months ago when it launched Office for Mac 2011.

Last fall, Apple set free its rival suite, iWork, giving away the three OS X applications of Pages, Numbers and Keynote to every new Mac buyer. In households -- but not businesses -- with multiple Macs, that effectively means all the machines can be equipped with iWork for free.

How Microsoft will deal with a free iWork is unknown. Currently, Microsoft charges $140 for the single-license Home & Student edition, $220 for a one-license copy of Home & Business, and $100 annually for an Office 365 subscription. Even that third option, with its five licenses, may seem pricy to Mac owners used to the free iWork and satisfied with its fewer features.

Also important is the ticking clock on Office for Mac 2011.

Microsoft supports Mac editions of Office for just five years, half the support lifecycle of the Windows' suite, and Office for Mac 2011's retirement date is not that far away: Jan. 12, 2016. Microsoft could extend support for Office for Mac 2011 -- it did that for Office for Mac 2004 -- but if it does not, it needs to provide a replacement soon to give customers time to migrate.

In the past, Microsoft has used the Macworld trade show and conference to demo its upcoming Office for Mac. This year, Macworld, now called "Macworld/iWorld," is slated to run March 27-29 in San Francisco. (The Macworld/iWorld conference is run by IDG, the parent company of Computerworld and its sister publication and website, Macworld.) However, Microsoft is not on this year's exhibitors' list for the trade show.

The next Office for Mac is already overdue by Microsoft's past practice of following the latest version for Windows within a year.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, or subscribe to Gregg's RSS feed . His email address is gkeizer@computerworld.com.