Flow is designed to fill the void between Flash and the Flex Framework. It takes best practices from Flex (such as MXML and Data Binding), but is designed to very lightweight, so it can (and should) be used in virtually any project that targets the Flash Player, where the Flex Framework is considered too heavy or too slow.

The Flow Framework implements best practices that I've gathered from my 10+ years creating Flash and Flex applications.

Flow borrows these from Flex:

1. MXML. Declarative programming is one big time-saver.
2. Contraint-based layout.
3. Data-binding. Once you hook up your views to data via data-binding, you swear never to go back again.
4. States. Coupled with declarative layout, states provide a fast way of putting together the visual layer of an app.
5. Transitions & Effects. I'm a sucker for smooth transitions in UI's. Flow's effects put Flex to shame.
6. Declarative graphics. Declaring shapes, fills and borders in MXML is just cool.

In addition to these Flex-based features Flow brings to the table:

1. Speed. Flow is optimized and fast. (err... or at least it will be ;))
2. File size. The Flex framework takes around 300kb without any components. Flow is 18kb.
3. Mix & match. Have a movie clip? Just put it in. Layout will still be able to deal with it.
4. Commands & CommandDispatch. A MVC micro-framework without all the boiler-plate.
5. Fire & forget loading of external assets.

If you have any questions, drop me a tweet.