Watch out, Macromedia. Here comes Microsoft "Sparkle."

According to press reports, Sparkle is an animation toolset that will likely emerge as part of the Longhorn wave of products/technologies. Some are describing Sparkle as a Macromedia "Flash killer."

Microsoft officials declined to comment on Sparkle. But here's what we hear:

Microsoft's graphics subsystem for Longhorn is code-named "Avalon." Avalon is designed to take the place of the USER/GDI graphics application programming interfaces (APIs) that are part of the current Win32 programming model.

Developers can write to Avalon using XAML, the Microsoft-authored eXtensible Application Markup Language. But for now, the only way to write XAML applications is to hand-code them.

Sparkle is the tool that will automate XAML application development. Said one source: Sparkle will let you create XAML and .Net applications."

Comparing Sparkle and Flash is "kind of an apples and oranges comparison," says one Windows developer familiar with Sparkle, who requested anonymity. "On the surface, it looks like Flash, but it's really a programmable 'thing' for doing stuff with Avalon. It's really designed more to make your existing applications do really cool stuff.

The developer continued: "Flash won't die because it's cross-platform and very easy for simple things, especially on the Web. Sparkle will just make it much easier for developers to do cool effects within their applications."

For example, according to one source, Microsoft used Sparkle to develop the clock that was part of the "Sidebar" that is part of the Longhorn Aero interface.

It's not clear when and whether Microsoft will release Sparkle to developers, although one would assume the company would do so before Longhorn is delivered (estimated to be 2006).

It's also not the first time word of Microsoft developing a "Flash killer" has leaked. A year ago, rumors of such a tool appeared in several Web postings. And more recently, based on information released around the Microsoft Professional Developers Conference last week, individuals have speculated that Microsoft is gunning for Macromedia with Avalon.