As we are doing all of our game development we often mix and match technologies. I came across this today and thought others besides myself might be interested in it. It is only Alpha code at this point, but reportedly some people have used it in production apps.
gameswf (pronounced "game swiff") is an open source Public Domain library for parsing and rendering SWF movies, using 3D hardware APIs for rendering. It is designed to be used as a UI library for computer and console games.
It is written in C++, and compiles under Windows, Mac OSX and Linux, using GCC and MSVC. It includes code for rendering with OpenGL. The rendering module is factored out so that you can port to other APIs.
It is currently being maintained as a semi-autonomous part of my personal tu-testbed project on SourceForge.
The biggest benefit of using SWF as a file format for game UIs is the availability of high quality authoring tools (like Macromedia Flash MX) and the large number of talented designers who have expertise with these tools. The SWF format is not perfectly suited for game UIs, but it's not bad, and my hope is that gameswf will help improve the quality of game UIs while reducing the effort that goes into making them.