Office has long been in a leadership position at Microsoft, and when it overtook Windows as the company's biggest business a few years back, many thought it had nowhere to go but down. Today, however, Office is leading Microsoft in a different way: It is on the bleeding edge of the firm's rapid release makeover, and with new products, services and updates arriving literally every week, I'm watching it more closely than ever.

Like many of you, I use and rely on Microsoft Office every day, and I've watched as a passionate observer as the product line has grown from apps to suites to servers to online services over the years. This transformation of course parallels the broader industry trends of which everyone reading this is well aware. But from the perspective of Microsoft and its offerings, one could make the case that using Office to test the waters of cloud computing and pervasive mobile device support was a bold and risky choice

This is, after all, Microsoft's biggest business (though the company no longer reports earnings as it did when it hit that milestone). A more conservative firm might have milked that business for all it was worth, while treading more lightly in new markets with new or different products.

Instead, Office did what leaders do: it led. And the last few years, the last few months, have been a dizzying whirlwind of releases. I've had a hard time keeping up with it all.

What's emerged, in broad strokes, is that Office, and thus the whole company, is thinking less about big bang releases interspersed with service pack-type updates and is thinking more about continuous updates. Today, we still have a product called Office 2013, of course, but that's mostly because customers are used to that sort of name and application bundling. But, if you're an Office 365 subscriber, you know that you can sign into your user portal and download and install "the latest version of Office," and do so across several PCs and other devices.

If you're really paying attention—and really, the goal is for this stuff to be seamless—you also know, or at least have some vague idea, that part of the Office 365 promise is that the locally installed Office applications you use so much will be kept up to date and improved regularly. But there are questions about this new approach. For starters, how regularly are these applications improved? Can customers have any say over how or when these changes are rolled out to their users?

According to the Office team's ever-evolving plans, the company plots long-, mid- and short-term updates. Short-term updates can happen as often as weekly and are generally just bug fixes and the like. Mid-term updates are those that will happen over the next 30-to-90 days, and these updates will soon feature a time-bombed opt-in period where customers can choose to test features before rolling them out more broadly. Long-term updates are more akin to the "big bang" releases of yore and may trigger new retail releases and versioning, as in the past.

Tony Redmond covered this topic in more depth recently in How new stuff is introduced through Office 365 Change Management. As he notes, the interesting thing here is the transparency. In the past, Microsoft would have kept all of this stuff secret. And while it still does hold off on communicating certain releases—like a new version of Office for some device platform, like iPad or Android tablets—it is much more open to customers about what's happening because that transparency is basically required in this new rapid release world. Microsoft seems to be acknowledging that if it's going to keep updating things, it likewise needs to inform business customers what's happening.

Rapid release isn't just about the suite and applications you install on your PCs, of course. By bundling Exchange, SharePoint and Lync Online in Office 365, Microsoft has stumbled into an interesting new paradigm by which it can now update the functionality those servers in tandem, something it couldn't do before to any great degree because most of its customers had only one or two of those products deployed. Suddenly, it's not about what any one of those products can do, it's about what they can do together. There will be fewer Exchange-specific updates and more updates that apply across Office 365. That's huge.

On the mobile front, the Office team has led the charge in supporting popular non-Microsoft mobile platforms—meaning iOS (iPhone/iPad) and Android—as well as (or even better than) its own Windows-based mobile platforms. That's why we see a full-featured Office suite for iPad today, and will most certainly see one on Android tablets before a similar "touch-first" Office appears on Windows sometime next year.

But it's not just the core mobile apps: Microsoft has released and updated an almost uncountable number of apps in recent months. Just this past week, Microsoft released a new (and pre-release) version of the ill-named OWA for Android, which brings the full feature set of Exchange Online-based email, calendar and contacts management to Android clients. It follows similar releases on iPhone and iPad, and will be improved in the weeks and months ahead. You know, because it's Office.

But anytime you make changes as rapidly as this, there are bound to be cracks. And indeed, there are times when I wonder whether Office might in fact be moving a bit too quickly.

That OWA for Android release, for example, is confusing some users and antagonizing others. It's only designed to work with a single Office 365 for business account, so it can't be used with on-prem versions of Exchange or other Exchange Online platforms, let alone multiple accounts. The name—OWA stands for "Outlook Web App"—is likewise confusing, as is the fact that modern Android devices support Exchange ActiveSync (EAS), leading some to question the need for a single, Outlook-like standalone app. This is an area where the firm should consider stepping back and explaining itself a bit more clearly.

Speaking of issues, a Windows Update that was released this past Patch Tuesday has apparently broken some Office installs, but only on PCs to which the software was deployed via Office 365. The bug will be fixed, and Microsoft is offering a workaround in the meantime, but this is the peril with rapid release: in racing so hard to update, update, update, any problem is like a sudden case of "rapid de-acceleration trauma". The problem turns into a hard crash, in other words.

Finally, the Office folks need to get their branding in order. OWA for Android is a terrible name, but is at least somewhat understandable. What is more problematic is that Microsoft offers something called Office 365 for both consumers and businesses, and while the latter offerings of course use tried and tested Exchange, SharePoint and Lync Online technologies, the former is based on . . . Hotmail. Which is of course confusingly named Outlook.com, which is further not the same as Outlook, nor is it based on Exchange. And while OneDrive and OneDrive for Business both share similar names and similar features, they are not based on the same technologies at all.

The whole thing is a mess. I get questions about these things all the time, and that so many people don't understand the differences between these offerings is all the evidence I need: Office needs to reevaluate its branding.

For Microsoft, Office stands as a testament to what's possible when a software company really does embrace the "mobile first, cloud first" strategy that CEO Satya Nadella endlessly touts. But it's also a warning, in some ways, about pushing forward too quickly. I suspect the rest of the company will adapt accordingly, and the bigger point, is that it's working despite some blemishes. Office really does seem to be pulling off this transition, speed bumps and all.