ActionScript is a scripting language based on ECMAScript. ActionScript is used primarily for the development of websites and software using the Adobe Flash Player platform (in the form of SWF files embedded into Web pages), but is also used in some database applications (such as Alpha Five). Originally developed by Macromedia, the language is now owned by Adobe (which acquired Macromedia in 2005). ActionScript was initially designed for controlling simple 2D vector animations made in Adobe Flash (formerly Macromedia Flash). Later versions added functionality allowing for the creation of Web-based games and rich Internet applications with streaming media (such as video and audio).

History

ActionScript started as a scripting language for Macromedia's Shockwave Flash authoring tool, now developed by Adobe as Adobe Flash. The first three versions of the Flash authoring tool provided limited interactivity features. Early Flash developers could attach a simple command, called an "action", to a button or a frame. The set of actions was basic navigation controls, with commands such as "play", "stop", "getURL", and "gotoAndPlay".

With the release of Flash 4 in 1999, this simple set of actions became a small scripting language. New capabilities introduced for Flash 4 included variables, expressions, operators, if statements, and loops. Although referred to internally as "ActionScript", the Flash 4 user manual and marketing documents continued to use the term "actions" to describe this set of commands .

Timeline by player

• Flash Player 2: The first version with scripting support. Actions included gotoAndPlay, gotoAndStop, nextFrame and nextScene for timeline control.

• Flash Player 3: Expanded basic scripting support with the ability to load external SWFs (loadMovie).

• Flash Player 4: First player with a full scripting implementation (called Actions). The scripting was a slash based syntax and contained support for loops, conditionals, variables and other basic language constructs.

• Flash Player 5: Included the first version of ActionScript. Used prototype-based programming based on ECMAScript, and allowed full procedural programming and object-oriented programming.

• Flash Player 6: Added an event handling model, accessibility controls and support for switch. The first version with support for the AMF and RTMP protocols which allowed for ondemand audio/video streaming.

• Flash Player 7: Additions include CSS styling for text and support for ActionScript 2.0, a programming language based on the ECMAScript 4 Netscape Proposal with class-based inheritance. However, ActionScript 2.0 can cross compile to ActionScript 1.0 byte-code, so that it can run in Flash Player 6.