A decade ago, when I used to publish electronic newsletters out of my home office and send them out to several thousand readers through a UNIX-based list server, I created a Microsoft Word macro that would format articles in a text email-compatible format. I didn't realize it at the time, but this fairly unsophisticated little macro, which lived in a toolbar button in the application, was one of many predecessors to what Microsoft is now calling Office Business Applications (OBAs). Today, OBAs are big money and, for those who use them, among the most productive software solutions out there.

OBAs are exactly what they sound like: applications that run within Microsoft Office applications such as Word, Outlook and Excel. In this sense, Office has become a platform, like Windows or Microsoft .NET, on which developers can create other solutions. Indeed, for all the talk about rival platforms like Java, Linux, or Apache, one can make an excellent case that Office is the second-largest platform on earth after Windows, given the sheer size of the market. Microsoft says that almost 500 million people worldwide use Office applications every day.

Microsoft created the OBA moniker and formalized and legitimized the market by moving much of its Office suite from antiquated Visual Basic for Applications (VBA) to more sophisticated .NET-based developer frameworks. And with the recently Office 2007, the company has taken OBAs to the next level by providing access to the new Ribbon user interface. Now, .NET-oriented developers can easily move into Office development, reuse existing code, and tie into back-end servers, including business process and business intelligence (BI) solutions, to the applications that their knowledge workers already know and love. That last bit is critical, because to date, utilizing the custom applications that come with BI and ERP solutions requires training and can be expensive.

Microsoft will highlight OBAs at its annual partner conference next week in Denver. (Microsoft CEO Steve Ballmer also talked up OBA at the Software 2007 conference in May.) Last week, I sat down with Daz Wilkin, a program manager in Microsoft's Platform Strategy Group, to discuss what the company has been doing in the OBA space. Not surprisingly, there's a lot going on: Microsoft has been creating reference OBAs for developers to study and work from, and more are on the way. Just last month, the company shipped its latest reference OBA, Consumer Engagement Reference Architecture for Health Plans. These aren't "starter apps for dummies," either, but fully functional and useful reference solutions.

"There's a schism in many enterprises right now," Wilkin told me. "Most knowledge workers aren't using LOB, ERP, or BI systems daily. The reasons are obvious: They're difficult to use and get data from, and it's often just easier to access old versions of the data in an Excel spreadsheet. Companies store their business processes in CRM and ERP, but there's lots of human workflow in there too, outside of the LOB apps. This is the world of OBA. We can automate those processes."

At a high level, I'm intrigued that OBAs are a poster child, of sorts, for Microsoft's "software + services" vision. Indeed, the company officially views itself not as a software company anymore, but rather as a software + services company. Because OBAs can tear down the virtual wall between familiar end-user applications like those in the Office suites and back-end services, they are an excellent example of software + services, even for the most risk-averse enterprises. And Microsoft isn't doing to a lot to get in the way of third parties: The company has created OBAs for its own SQL Server and Dynamics products, but beyond that, the company is pretty much just promoting the platform and showing the way.

I'll provide some useful links for those interested in OBAs once the Microsoft Partner Conference is under way.