Parsley

http://www.spicefactory.org/parsley/docs/2.2/manual/

Messaging

Reference:
http://jacobschatz.com/?p=345
http://www.lonhosford.com/lonblog/2010/09/14/basic-parsley-framework-flex-example-explained/
http://jimmyflex.blogspot.hk/2010/12/parsley-framework-basics.html
http://joelhooks.com/2009/07/14/inversion-of-control-and-dependency-injection-with-flex-using-the-parsley-application-framework-part-2/