Perhaps a lesser known framework for building Flash projects, CASA Lib (formerly CASA Framework) is a nice package of helpers and loose structure for constructing your actionscript world. CASA Lib is the ongoing work of Aaron Clinger and Mike Creighton, both previously working together at Odopod.

I've worked on a couple of projects with Mike and seen his use of CASA Lib first hand. Mike does really nice work, and on that merit alone I'm taking a long look at how CASA Lib can help me.

I've used Cairngorm in Flex and goofed around with EasyMVC and PureMVC. For Flex, Mate is another one out there that seems to be getting more and more buzz. There is a LOT of information about frameworks for Flex and Flash out there, but not a ton of consensus or guidance from what I've seen. Finding best practices for developing Flash/Flex is a real chore, not that it's ever easy in any technology given how opionated developers can be.

CASA Lib is really something completely different. I think with my current understanding I would characterize it more as a loose framework built with a bagful of the most frequently used helper methods for things such as loading xml data, destroying instances, event handling and other tasks.

Check it out and let me know what you think.