Adobe® Flex® Builder™ 3 software is a highly productive Eclipse™ based development tool enabling intelligent coding, interactive step-through debugging, and visual design of the user interface layout, appearance, and behavior of rich Internet applications (RIAs). Flex Builder 3 is now available in Standard and Professional editions.

Powerful coding tools
Flex Builder 3 is a powerful Eclipse based IDE that includes editors for MXML, ActionScript™, and CSS, as well as syntax coloring, statement completion, code collapse, interactive step-through debugging, and more.

Rich visual layout (Enhanced in Flex Builder 3)
Visually design and preview user interface layout, appearance, and behavior using a rich library of built-in components. Extend the built-in components or create new ones as needed.

New in Flex Builder 3 — Interactively set and preview CSS values on any of your components in Flex Builder Design view.