Core ECMAScript-compliant ActionScript classes are in the Top Level package. The flash.* packages contain the ActionScript classes for Adobe® Flash® Player 9.

Flex classes are in the mx.* packages.


 PackageDescription
 Top LevelThe top level contains the core ActionScript classes and global functions. 
 flash.accessibilityThe flash.accessibility package contains classes for supporting accessibility in Flash content and applications. 
 flash.displayThe flash.display package contains the core classes that the Flash Player uses to build visual displays. 
 flash.errorsThe flash.errors package contains a set of commonly used error classes. 
 flash.eventsThe flash.events package supports the new DOM event model and includes the EventDispatcher base class. 
 flash.externalThe flash.external package contains the ExternalInterface class which can be used to communicate with the Flash Player's container. 
 flash.filtersThe flash.filters package contains classes for bitmap filter effects. 
 flash.geomThe flash.geom package contains geometry classes, such as points, rectangles and transformation matrixes, to support the BitmapData class and the bitmap caching feature. 
 flash.mediaThe flash.media package contains classes for working with multimedia assets such as sound and video. 
 flash.netThe flash.net package contains classes for sending and receiving from the network, such as URL downloading and Flash Remoting. 
 flash.printingThe flash.printing package contains classes for printing Flash-based content. 
 flash.profilerThe flash.profiler package contains functions used for debugging and profiling ActionScript code. 
 flash.systemThe flash.system package contains classes for accessing system-level functionality, such as security, multilanguage content, etc. 
 flash.textThe flash.text package contains classes for working with text fields, text formatting, text metrics, style sheets, and layout. 
 flash.uiThe flash.ui package contains user interface classes, such as classes for interacting with the mouse and keyboard. 
 flash.utilsThe flash.utils package contains utility classes, such as data structures like ByteArray. 
 flash.xmlThe flash.xml package contains Flash Player's legacy XML support, and other Flash Player-specific XML functionality. 
 mx.binding.utilsThe mx.binding.utils package contains the classes for creating binding watchers and for defining bindings in ActionScript. 
 mx.chartsThe mx.charts package contains the classes for Flex Charting. 
 mx.charts.chartClassesThe mx.charts.chartClasses package contains the base classes for the Flex charting components. 
 mx.charts.effectsThe mx.charts.effects package contains the effect classes for the Flex charting components. 
 mx.charts.effects.effectClassesThe mx.charts.effects.effectClasses package contains the effect instance classes for the Flex charting components. 
 mx.charts.eventsThe mx.charts.events package contains the classes that define chart event objects. 
 mx.charts.renderersThe mx.charts.renderers package contains the item renderer classes for the Flex charting components. 
 mx.charts.seriesThe mx.charts.series package contains the series classes for the Flex charting components. 
 mx.charts.series.itemsThe mx.charts.series.items package contains the items series classes for the Flex charting components. 
 mx.charts.series.renderDataThe mx.charts.series.renderData package contains the data classes for the Flex charting components. 
 mx.collectionsThe mx.collections package contains the classes for the Flex collection components. 
 mx.collections.errorsThe mx.collections.errors package contains the error classes for the Flex collection components. 
 mx.containersThe mx.containers package contains the container classes. 
 mx.containers.accordionClassesThe mx.containers.accordionClasses package contains the classes used by the Accordion container. 
 mx.controlsThe mx.controls package contains the Flex user-interface controls. 
 mx.controls.dataGridClassesThe mx.controls.dataGridClasses package contains the classes used by the DataGrid control. 
 mx.controls.listClassesThe mx.controls.listClasses package contains the classes used by the list-based controls. 
 mx.controls.menuClassesThe mx.controls.menuClasses package contains the classes used by the menu-based controls. 
 mx.controls.scrollClassesThe mx.controls.scrollClasses package contains the classes used by controls that support scroll bars. 
 mx.controls.sliderClassesThe mx.controls.sliderClasses package contains the classes used by the Slider control. 
 mx.controls.textClassesThe mx.controls.textClasses package contains the classes used by the text-based controls. 
 mx.controls.treeClassesThe mx.controls.treeClasses package contains the classes used by the Tree control. 
 mx.controls.videoClassesThe mx.controls.videoClasses package contains the classes used by the VideoDisplay control. 
 mx.coreThe mx.core package contains the base classes and interfaces, such as UIComponent, used by Flex. 
 mx.dataThe mx.data package contains classes for working with the Flex Data Management Service. 
 mx.data.errorsThe mx.data.errors package contains the error classes used with the Flex Data Management Service. 
 mx.data.eventsThe mx.data.events package contains the event classes used with the Flex Data Management Service. 
 mx.data.messagesThe mx.data.messages package contains the messages used with the Flex Data Management Service. 
 mx.data.mxml 
 mx.data.utils 
 mx.effectsThe mx.effects package contains the Factory classes to support behaviors. 
 mx.effects.easingThe mx.effects.easing package contains the easing classes used by effects. 
 mx.effects.effectClassesThe mx.effects.effectClasses package contains the effect implementation classes corresponding to the effect factory classes in the mx.effects package. 
 mx.eventsThe mx.events package contains the classes that define Flex event objects. 
 mx.formattersThe mx.formatters package contains the classes to support data formatting. 
 mx.graphicsThe mx.graphics package contains drawing classes. 
 mx.loggingThe mx.logging package contains the logging classes. 
 mx.logging.errorsThe mx.logging.errors package contains the error classes used by the logging components. 
 mx.logging.targetsThe mx.logging.targets package contains the target classes used by the logging components. 
 mx.managersThe mx.managers package contains the Flax manager classes, such as DragManager and HistoryManager. 
 mx.messagingThe mx.messaging package contains the messaging classes used with Flex Data Services. 
 mx.messaging.channelsThe mx.messaging.channels package contains the messaging channel classes used with Flex Data Services. 
 mx.messaging.configThe mx.messaging.config package contains the messaging configuration classes used with Flex Data Services. 
 mx.messaging.errorsThe mx.messaging.errors package contains the messaging error classes used with Flex Data Services. 
 mx.messaging.eventsThe mx.messaging.events package contains the messaging event classes used used with Flex Data Services. 
 mx.messaging.managementThe mx.messaging.management package contains the bean management classes used with Flex Data Services. 
 mx.messaging.messagesThe mx.messaging.messages package contains the message classes used with Flex Data Services. 
 mx.preloadersThe mx.preloaders package contains the classes used by the download progress bar. 
 mx.printingThe mx.printing package contains the printing classes. 
 mx.resourcesThe mx.resources package contains the classes used to support localization. 
 mx.rpcThe mx.rpc package contains the RPC classes. 
 mx.rpc.eventsThe mx.rpc.events package contains the RPC event classes. 
 mx.rpc.httpThe mx.rpc.http package contains the HTTPService classes. 
 mx.rpc.http.mxmlThe mx.rpc.http.mxml package contains the HTTP service MXML classes. 
 mx.rpc.mxmlThe mx.rpc.mxml package contains the RPC MXML interface. 
 mx.rpc.remotingThe mx.rpc.remoting package contains the remote object classes. 
 mx.rpc.remoting.mxmlThe mx.rpc.remoting.mxml package contains the remote object MXML classes. 
 mx.rpc.soapThe mx.rpc.soap package contains the web service classes. 
 mx.rpc.soap.mxmlThe mx.rpc.soap.mxml package contains the web service MXML class. 
 mx.rpc.xmlThe mx.rpc.xml package contains the RPC XML-related classes. 
 mx.skinsThe mx.skins package contains the classes that define the skinning components. 
 mx.skins.haloThe mx.skins.halo package contains the classes used to skin Flex user-interface controls. 
 mx.statesThe mx.states package contains the classes to support view states. 
 mx.stylesThe mx.styles package contains the classes used by the Flex styles components. 
 mx.utilsThe mx.utils package contains Flex utility classes. 
 mx.validatorsThe mx.validators package contains the classes to support data validation.