This topic is touched on in this article. But it's an inevitable question -- why did Stardock develop the .dream format?
A little history here -- Microsoft has created a cool new feature in Windows Vista Ultimate called Windows DreamScene. Concurrently, Stardock was developing its own animated wallpaper program called DeskScapes. Early in development, it was decided it made a lot more sense to team up.
Windows DreamScene allows users of Windows Vista Ultimate to play video as animated wallpapers. The concept is very straight forward -- .MPEG or .WMV as animated wallpaper.
Stardock's view was that we wanted to take it one step further and address potential problems that might come up.
Giving artists credit...
For instance, look at your wallpaper choosing dialog in Windows Vista (or even XP). There's no credit or author info on who made the wallpaper. Maybe that wasn't an issue back in the day of making bitmaps for wallpapers that didn't require effort. But believe us, creating a decent animated wallpaper can take weeks. We strongly believe that artists would want to get credit for what they've done.
Finding the stuff...
Trying to find an animated wallpaper on the Internet? Good luck. Look for .WMV or .MPEG? Or maybe type in "animated wallpaper" and find all sorts of weird stuff. People who make this stuff are going to want to find it. That's one of the reasons we wanted to create a specific extension for animated wallpapers so that people would be able to know that THIS was created to be an animated desktop and isn't just some random video.
Extending the capability...
This has been discussed elsewhere but playing video as the wallpaper is just the beginning. The natural next step is dynamic content. DeskScapes provides that capability. Same for triggers (events that change what is being played as the wallpaper). In the coming weeks, we'll begin posting the documentation and examples on creating this sort of thing along with samples.
Providing a community site...
Another thing that is important that I don't know if most people realize is that for this sort of thing to take off, you need stable, reliable, trustworthy sites to host and provide a base for this kind of thing. 100,000 people downloading a 50 megabyte file is simply beyond the capability of most sites. And while torrents and such might solve some of that, you're still stuck with having to hunt and peck for things rather than see what you're getting and talk to the people who made them directly.
So that's why we created the .dream format. It does create some confusion initially that it's not part of Windows DreamScene. That may change in the future as the format matures, but obviously initially the extra step of downloading DeskScapes can be a hassle for some but on the other hand, because we're not Microsoft, we have a lot more latitude on what we can do in the short-term.
As for us at Stardock, we're just jazzed that animated wallpapers are finally a practical reality (they've been around in impractical forms for years -- even on OS/2 <g>).