The document introduces Reflex, a new AS3 component library that allows building user interfaces with MXML without requiring Flex. It provides concise components like buttons, lists and containers that support features like layouts, data binding, skins and states in a lightweight package compared to Flex. The presentation outlines key Reflex concepts like its customizable and pay-as-you-go nature, support for Flash and mobile development, and how behaviors, containers and lists work.