Another option besides ActiveSWF is the recently announced Xamlon Pro Flash Edition. Xamlon is essentially an implementation of XAML the current version of Visual Studio. There’s a version for Windows Forms, for Compact Framework and now for Flash. So basically, you can write your flash app with XAML and C#. Apparently, you can also code directly to the Flash format, bypassing the XAML layer entirely. I like the idea of using a managed component like Xamlon better than a COM based component.