With the next Office wave of products and services set to launch at the end of the month, it’s time to turn our attention to what I see as Microsoft’s most innovative and lucrative business. This is arguably the most important Microsoft launch of 2013, and can arguably be seen as the conclusion of the firm’s other product launches from late 2012.

I’ll have a formal review in the future, as well as ongoing series of article about Office 2013 tips and features. For now, let’s just take a step back and remember how we got here, and how this next Office wave changes things.

The return of multi-platform

Office is one of Microsoft’s longest-lived product lines, especially if you date it back to the original Multiplan from 1982. (Which you should, as Multiplan eventually morphed into Excel.) Multiplan was a multi-platform product that ran on CP/M, MS-DOS, Xenix (a Microsoft version of UNIX), Commodore 64, Texas Instruments TI-99/4A, Radio Shack TRS-80 Model II and 100, Apple II, and other systems. And that’s the first interesting fact about Office 2013, because with this release, Microsoft will return to the product-line’s multi-platform roots.

Sure, Microsoft kept a semi-crippled version of Office:Mac going for years too, but let’s be serious: That product existed only to keep antitrust regulators at bay, and anyone who’s used both the Mac and Windows versions of Office know that Microsoft never did a particularly good job of making Office a representative Mac application suite (especially in the OS X versions), nor of keeping it up to speed with the features in the Windows version.

With the Next Office, Microsoft is expanding the range out quite a bit. This wave of Office products will include, in addition to the Windows versions, a vastly improved Web-based Office Web Apps version that will for the first time be a viable alternative to natively installed applications and, over time, native Office versions for iPad and Android tablets. (These are expected later in the year and won’t be launched in late January.) Microsoft will also update the Mac suite at some point, meaning that by the end of 2013, there will be a version of Microsoft Office available for every major computing platform on earth. Just as with Multiplan in 1982.

Office as a subscription

While Microsoft has tried to foist subscription-based versions of Office on consumers for a few versions now, always unsuccessfully, Office 2013 is the first that gets it right. The issue in the past was that subscription versions of Office simply repackaged the then-current product, and you could figure out how many months needed to go by before you had “beaten” the price of simply buying Office outright. It was rarely a terrific deal for users.

With Office 2013, Microsoft has changed the licensing of Office to match licensing of mobile apps. That is, rather than tying the purchase of Office to a single PC as was done in the past, the subscription-based versions of Office 2013—which are sold through Office 365—tie Office to you, the user. And you get multiple PC/device install rights, not just the ability to install to a single PC, and those rights are transferable on the fly. Furthermore, Microsoft explicitly condones family sharing of these licenses so that you can provide Office 2013 to all the PCs in your house. In these ways, Office as a subscription finally benefits users and Microsoft, the latter of which gains what it has always wanted, a steady regular income (as opposed to single, lump purchases every 3 to 5 years).

By subscribing to Office, you also get continual updates, including to major new product versions, so you’re not stuck on the same version indefinitely.

Learn more: Office 2013: Pricing and Packaging

Office as a service

Tied to the Office subscription is the fact that Office 2013 will be delivered as an online service, through Office 365 subscriptions. Yes, you will still install Office locally on your PCs and devices. But the way you will do so has changed dramatically thanks to advances in a technology called Click-to-Run, which was previously offered as a way to blast Office installs on PCs in an enterprise. With Office 2013, this technology is used to blast Office onto your PCs, over the Internet, at speeds that will surprise you. And as exciting, perhaps, though it’s not well understood by most users yet, you will also be able to use a feature called Office On Demand to use the Office application on PCs you don’t use. When you’re done, the install is wiped out immediately as if it were never there. Amazing.

Learn more: Office 2013 Feature Focus: Click-to-Run

Learn more: Office 2013 Feature Focus: Office on Demand

Cloud integration

Office continues operating like an online service even after it’s installed because it integrates with Microsoft’s online cloud services—SharePoint Online (and on-premise) for businesses and SkyDrive for consumers—and in fact uses those services as the default save point for documents so that they will be available anywhere at any time and on any device. This is a huge functional change for the suite, so that even those who are not using the SkyDrive desktop application—which syncs SkyDrive content to your PCs—will benefit from this integration. Sure you could always save documents to your Documents library as before. But with this integration, your data won’t be locked to a single hard drive on a single PC. By default.

Learn more: Office 2013 Public Preview: SkyDrive Pro

Metro to the future

In the mid-2000’s, it seemed as if Office had run its course. After all, what could you do to improve a word processor or spreadsheet in any meaningful way? A lot, as it turns out. By adding the innovative and truly useful new ribbon user interface to Office 2007 and then improving it dramatically over both Office 2010 and Office 2013, Microsoft has shown that thinking outside the box can improve productivity and feature discoverability while removing overloaded legacy user interfaces and making something old seem new again. Brilliant.

Office 2013 takes this user experience revolution to the next step by embracing the Metro design ideals, which minimizes the user interface “chrome” while making the UI that does remain more subtle so that users can focus on the content. Office 2013 applications are also designed work to work better with multi-touch via a new Touch Mode, and in full-screen usage closely mimic true Metro-style apps, a hint, I think, at future Metro-style Office versions. (Two Office 2013 offerings are available as Metro-style apps already, OneNote and Lync.)

More to come…

There are a lot of specific new features and functionality to discuss going forward, but I wanted to highlight some of the important high-level changes to the next Office that really set it apart from its predecessors and make this suite a viable and desirable productivity tool even on the highly mobile computing devices of the near future. We’re still in the middle of a tsunami of change, but it’s interesting to me that Office is still leading the charge and doing so in ways that are not nearly as controversial or debatable as what’s happening with, say, Windows 8 and RT. I argue that it is Office, not Windows, that is Microsoft’s most important franchise, and that Office 2013 is yet another indication that this aging software giant can successful manage deep technological change like no other.

More soon.