Pretty vague. As you’d expect. In this excellent interview Microsoft’s developer division VP Scott Guthrie cites three revenue opportunities:

• Tools and servers
• Customer engagement leading to ad sales
• As a platform for other, presumably profitable, apps

I’m most interested in the third of these. By the way, I like Silverlight. Cross-platform .NET has been a personal interest of mine for ever. In 2002 I wrote an introductory article about .NET, and said:

It would do .Net enormous good if it became a credible cross-platform contender, say on Windows, Linux and the Mac. It would do Microsoft enormous good if it could be seen to work with the open source community in the same way as IBM does so successfully.

Six years on, the cross-platform potential in .NET is finally coming together. However, it is as a web-based runtime, rather than as a desktop runtime. That wasn’t quite what I expected back in 2002, but it is no bad thing. If Microsoft is serious about refactoring all its software for cloud services, as Ray Ozzie stated at Mix08, then Silverlight could be a key enabling technology, giving a rich desktop-like experience but in browser-hosted applications.

I was also interested in Guthrie’s comments on open source:

…people in the Linux community are much more likely to trust Novell and, specifically, Miguel [de Icaza] and the Mono Project and feel like, “Okay — if it is open source, I can get access to all the source [code]. You’re telling me that I can snap the source and build it myself if you’re not doing a good job? Okay, that’s interesting.” The higher level libraries that we are distributing — our controls and things like that — those will just work on the Linux version of Silverlight. They can take our source and use them for that.

Microsoft isn’t posting its source for the Silverlight runtime, but it is supporting an official open source implementation. That’s an intriguing distinction versus Flash, which has open source implementations none of which have taken off. Adobe has open-sourced Flex, but not the Flash runtime. However, note Guthrie’s comment:

We actually deliver the media graphics stack to Novell, so we use the same video pipeline and same media pipeline on the Linux version as on the Windows and Mac versions.

So that “media graphics stack”, is that open source? I suspect not but would be glad to be proved wrong. This point might make a difference to Linux distributions that exclude proprietary software by default.

Finally, Guthrie makes some remarks about Adobe AIR and the fact that Silverlight doesn’t have an equivalent cross-platform desktop engine. He says businesses are more interested in a “web-based model”, and observes that the full .NET and WPF stack is already a desktop runtime.

I’m not sure that this is a big deal. It wouldn’t be a huge step to host Silverlight in a cross-platform desktop application, for example by including it in a browser control. At the 2007 Mix, the New York Times folk told me they intended to do this with Times Reader. We are also going to see a number of different approaches to this problem. Mozilla is working on desktop integration for browser apps. Google shows a desktop shortcut in its introductory video for offline access. I recall Adobe’s Kevin Lynch remarking on the psychological barrier to opening a browser application when offline, as being one of the motivations for developing AIR, but there is more than one way to mitigate this.