Adobe Flex 3 is a highly productive open source framework for building rich web applications that can be deployed across browsers and desktops using Adobe AIR. It uses MXML and ActionScript languages that compile to runtimes allowing applications to have rich user interfaces and integrate with various data sources and APIs. Adobe AIR further allows developers to use existing web technologies to build and deploy desktop applications with access to file systems and devices while maintaining security through signing, encryption, and sandboxing of applications.