One great feature of Groove V3 is folder-synchronization workspaces. These are just Windows folders -- on your desktop, or anywhere else on the filesystem -- which are also Groove workspaces.

On the one hand, they behave like Windows folders. You can open them, drop files into them, doubleclick files to launch them, and so on.

And on the other hand, they behave like Groove workspaces. You can invite people to them; those invitees get their own synchronized copy. Any changes in your local version are securely shared with the other members (and you don't need to be online at the same time, it just works). Anything they do, you see. New or changed items in the workspace show an "unread" flag. Groove pops up a little notifier when there's new content, or when people enter the workspace. You can even control whether you download all files automatically, or you want to manually download files over a certain size when it's most convenient. There's a little sidebar showing whether the members of the space are online. Doubleclick one of the members to send them an instant message. Open the chat pane and chat with them.

These workspaces are listed on the Groove launchbar, just like "normal" Groove spaces. Doubleclick the launchbar entry, and the folder opens.

So, this is all pretty awesome. File-sharing workspaces are great for working on documents in a team; also just for sharing current versions of files between, say, your work and home machines.

It's also a really significant view of what Groove's platform services are all about. We took a familiar user environment - Explorer - and outfitted it with Grooviness, to create a seamlessly shared environment which is at the same time completely familiar and normal, yet also enabled for collaborative groups to work in.

Now you can do this too. (By you, I mean you-if-you-build-software-of-any-sort). The kind of extensions to Explorer are available to YourApplication really transparently and quite easily. The V3 GDK includes a sample called "AppLauncher", which I'll talk about in some detail next.