Cairngorm is an ActionScript 2.0 and 3.0 framework that can be used to build more complex Flash and
Flex applications. It is based upon industry-standard programming design practices and provides a
robust Model-View-Controller (MVC) architecture to build upon.
When should you use it? When you are tasked to build a fairly large application, Cairngorm can help
you build something that is architecturally sound.
Any alternatives? Many open source pattern-based frameworks exist; however, few offer mature Flex
support. Of particular note is PureMVC (http://puremvc.org), an ActionScript 3–based framework
that is emerging as a serious competitor for Cairngorm. For ActionScript 2.0 development, it might be
worth looking at ARP (http://osflash.org/arp), developed by Flash guru Aral Balkan.