I got the following question from Aaron:

Why isn't all mac software from the MacBU? Do you talk to MS devs who are working on mac software but aren't in the macBU?

Silverlight and Expression Media (neé iView Pro) are two Mac apps that don't come from MacBU. Microsoft is expanding its product offerings to meet the needs of users across multiple platforms. The development of additional technologies on the Mac is a sign of Microsoft's commitment to the platform.

So why isn't all Mac development in MacBU? It's about aligning interests. MacBU is a pretty big team (we're currently at more than 200 people, and we're in the middle of a growth spurt right now) that's focused on delivering productivity apps. Bringing them into MacBU at this time would shift our focus away from that goal. It would also take those teams away from those who they need to collaborate with the most. Silverlight and Expression are still small teams (at least, when you compare them to the huge structure that comes in the Windows Office organisation), so they're able to do a great job of juggling the needs of both Windows users and Mac users while sitting together.

This doesn't mean that we don't work together. Internally, we help each other out. There is a lot of cross-pollination going on — there are several MacBU alums who have moved on to other roles in other Mac teams at Microsoft. There are other teams who are interested in knowing about the needs of Mac users as well, such as when the Office Live team adding support for Mac browsers. We share our expertise with those other groups so that they can take advantage of the years of Mac development experience that we've built up here.

It's nice not to be the only Mac developer at Microsoft. It's pretty cool to see what other teams are up to.