Adobe Flash

Adobe Flash, also called just "Flash", is a multimedia platform designed to make web apps, including ads and Browser-Based Games. All Nitrome games are written in Flash. Flash has an internal Programming Language called ActionScript.

ActionScript
ActionScript is the Programming Language that is used with Adobe Flash. It is based on Java, but is not the same a Java. It is mainly used in combination with Flash, but sometimes can be found working without Flash.

Trivia

 * A reliable way of checking if a game/ad is written in Flash or not is by right clicking it. If it says "About Adobe Flash Player 8/9/10", it is written in Flash. All Nitrome games on the site showed this, so all of them are written in Flash.