Flex is a highly productive, free and open source framework for building expressive web applications that can deploy consistently across major browsers, desktops, and operating systems. It uses a combination of ActionScript for programming and MXML for user interfaces. Flex applications provide rich user experiences with capabilities like multimedia playback, 3D graphics, video/voice chat, and camera support. Flex allows for rapid prototyping, low cost development and painless distribution for businesses and programmers.