The big difference is that Hype and Edge use CSS properties for animation. The image composition is built up from <div> elements whose style properties are modified by JavaScript. This means the animation capabilities are limited to those properties that can be expressed using CSS -- although this is not such a bad limitation at all, because CSS3 is now so powerful and starting to be widely supported.
Radi operates on a lower level to render its animations in HTML. Layers in Radi don't directly become <div> elements in the output; instead, the layer content is rendered either within <canvas> or <video> elements. You can use both together, for example using canvas to overlay some dynamic graphics context on top of a video.
To me, the capability to render content seamlessly to either video or canvas is the most unique thing about Radi. Although I'm still not quite sure how to express that as a benefit to the user, rather than a tech-spec curiosity... :)
(It's possible to do some limited CSS animation in Radi as well. There's a concept called "timeline events" that can be used to animate top-level element properties, so you can also use this model of animation on top of the canvas/video rendering... But it's currently limited to opacity only, so this feature is very much in its infancy.)
Radi operates on a lower level to render its animations in HTML. Layers in Radi don't directly become <div> elements in the output; instead, the layer content is rendered either within <canvas> or <video> elements. You can use both together, for example using canvas to overlay some dynamic graphics context on top of a video.
To me, the capability to render content seamlessly to either video or canvas is the most unique thing about Radi. Although I'm still not quite sure how to express that as a benefit to the user, rather than a tech-spec curiosity... :)
(It's possible to do some limited CSS animation in Radi as well. There's a concept called "timeline events" that can be used to animate top-level element properties, so you can also use this model of animation on top of the canvas/video rendering... But it's currently limited to opacity only, so this feature is very much in its infancy.)