From Manitu Group:
Action Script Viewer is a decompiler for SWF (Flash) files. It allows you to inspect ActionScript elements in (version 3,4,5 and 6/MX) SWF files and provides information about frames, instance names, symbols, movie clips, and other properties. A timeline and a context-sensitive preview are included. Action Script Viewer works with files created in Macromedia Flash 3, 4, and 5, as well as Flash MX.