Por ahí encontré esto, tal vez les resulte interesante...
MTASC : Motion-Twin ActionScript 2 Compiler
MTASC is the first ActionScript 2 Open Source free compiler. It can compile large number of .as class files in a very short time and generate directly the corresponding SWF bytecode without relying on Macromedia Flash or other tools. You can download it now and please read the comparison between MTASC and Macromedia compiler that is sold with Flash. If it's your first time using MTASC, please read how to install and use MTASC.
el link:
http://team.motion-twin.com/ncannasse/mtasc.html