New Flex MDI framework
True Agile released the first production ready version of their open source Flex/AS3 library for developing MDI applications.
You can check online example at what the library can do at:
http://www.trueagile.org/examples/amdiBasicExample/amdiBasicExample.html
You can see the online source code of that example at:
http://www.trueagile.org/examples/amdiBasicExample/srcview/
To follow the development in sourceforge:
https://sourceforge.net/projects/appmdi
Looks cool !