Recently, someone asked me if there was a way to tell if a SWF was created with Flex or not. After all, there are some non-Flex frameworks for building Flash/AIR SWFs, and the very first SWF application I ever saw that had a form to fill out was built with Adobe Flash Professional.
The answer is yes, assuming you can get your hands on the SWF. All Flex SDKs (Apache or Adobe) ship with a tool called swfdump. If you run “swfdump -abc myswf.swf > myswf.txt” you’ll get a huge pile of output in myswf.txt. Then if you open it in an editor, you can search for things like “SystemManager” and “UIComponent” and other Flex classes.
Note: You may also notice in myswf.txt that there is metadata in “RDF” format in a SWF that seems to indicate that the SWF was built with Flex. But it turns out the Flex SDK compilers will inject that metadata in every SWF regardless of whether you used the Flex SDK or some other framework or no framework at all.