Summary
Flash Player contains a set of core APIs that are always present when the Flash Player runs a SWF file. These APIs can be supplemented with additional APIs defined in ActionScript.
Popular Adobe content creation tools (Flash, Flex) include different ActionScript frameworks to facilitate interface components and other custom features. The Flash authoring tool was the first to do this with the ActionScript 1.0 components in Flash MX. With the introduction of Flash MX 2004 and ActionScript 2.0, the ActionScript 1.0 components were re-written in ActionScript 2.0. These components were known as the V2 components and were defined in a package namespace called mx. They continue to remain the standard component set for ActionScript 2.0 projects.
With ActionScript 3.0, the mx framework became the Flex framework. Since Flex tookover the mx package namespace, Flash CS3 created a new namespace for their ActionScript 3.0 components, fl.
ActionScript 2.0:
- mx package: Flash authoring tool framework
ActionScript 3.0:
- mx package: Flex framework
- fl package: Flash authoring tool framework
Note: Anything in the flash package is native to Flash Player.