Back in November, Microsoft announced that it would add Yammer Enterprise to its many Office 365 Enterprise offerings. Today, Yammer Enterprise heads out to an even bigger audience: It is being added to Office 365 Midsized Business and Education as well.

If you're not familiar, Yammer is Microsoft's enterprise-class social networking service. It's a replacement for, and superset of, the social features that Microsoft had previously built into SharePoint. (Which will still be supported, of course, but not updated.) There are mobile apps available for Windows Phone, iPhone/iPad, and Android. It was originally a standalone company that Microsoft purchased for $1.2 billion in 2012.

Since acquiring Yammer, the software giant has worked to integrate its technology in Office 365 and elsewhere. But it's also moved quickly to build Yammer-inspired social experiences across the Office stack. You can see this most clearly in the coming Office Graph functionality, which maps relationships between people and information by examining email, social conversations, documents, sites, instant messages, meetings, and more, on the fly. This functionality, which will work across Office, is an extension of something Yammer called Enterprise Graph, and it's all the more powerful because it obviously works across so much of Office now.

A related feature, codenamed Oslo, will help users find people within an organization that have specific skills, helping them reach out to those who can most obviously get something done.

And a third coming feature, Groups, will extend what was once just a Yammer feature across all of Office as well. Microsoft says that it will "unify people, profiles, conversations, email, calendars, and files across the entire set of Office 365 applications." It's sort of like SharePoint in that it's something a user can provision, except in this case what you're getting isn't just a shared document library, it's an inbox, social feed, calendar, and document library for everyone in the group. The point here is that people can stay up to date and contribute the way they want: Some people prefer email, some prefer social feeds, and some prefer calendar notifications. The Groups Experience will work for virtually anyone.

OK, so that's all very interesting. But today's news is about the expansion of Yammer Enterprise specifically. This version of Yammer adds a number of features to Yammer Basic—which supports conversations, user profiles, inbox, feeds, Groups-based collaboration functionality, and access to the mobile apps—with granular administration tools, a Yammer-based predecessor to Oslo, single sign-on with Office 365 and better integration with SharePoint, and other features. And while it was previously only available to Office 365 enterprise users, it's now available to those in both Office 365 Midsized Business and Office 365 Education (which I think was previously called Academic).

"This simple licensing change significantly reduces the friction in cross-organization collaboration and will enable your users to work with customers, partners, and parents and students without having to worry about additional costs," Microsoft's Jared Spartaro writes in a new post to the Office Blogs. "We're excited about what Yammer can do for these organizations. Midsized companies are always looking for ways to increase revenue, and schools are under increasing pressure to do more with less. Yammer and Office 365 can help your business or school work like a network and achieve your goals."