Scaleform is the leading provider of Flash-based user interface (UI) tools and middleware for video games.
Scaleform GFx is included in UDK. What's included:
GFx runtime player with 3Di rendering, CLIK Flash UI Framework, Scaleform IME for Asian language chat support, AMP profiler for performance and memory, game UI samples - HUD, menu, 3d inventory and loading screen, docs, videos, and demos.
What isn't included: Scaleform video and content authoring tools.
UDK Scaleform documentation: