One of my previous projects were showcased on Adobe Max 2008 in San Francisco, a mission planning system for NATO AWACS, E-3A Component, presented by
Peter Martin and
Mansour Raad.
The application was built based on Flex, LiveCycle DataServices and Oracle, one of the main components used within Flex was the ESRI mapping api.
The presentation is available on AdobeTV.
Who said Adobe Flex couldn’t be used for critical systems? 
If Adobe wants Flex to be seen as a serious framework in the enterprise, this is the kind of projects they need to show more of.
Over a series of posts I will cover some of the experiences gathered from this and other projects I have taken part in. There is usually more to a project then just choosing a framework like Cairngorm, PureMVC or one of the many IoC containers which are popping up everywhere.
I am developing a topic map-based knowledge management and repository application with Adobe Flex and Adobe AIR: http://www.quesucede.com/page/show/id/polishedcode. The experience is a good one. The Platform is very productive. Flex allows the developer to build very rich desktop-like user interfaces with all the advantages of being accessible over the web.