The source can be access on github at this location:
The license info is in the README file.
If you would like to get involved in publishing / updating this project at mozilla.org, please email me and I will add you as a new Author.
Recently a FlashBuilder project I was working on just stopped compiling using the debugger. The program would just hang with the build progress stuck on 57%. I tried many things to fix this, including uninstalling and reinstalling the debug versions of the Flash player without any luck. Eventually I found that the player that was launching was not the Debug player but the Release build. I discovered that once I changed the file preferences for SWF files it would debug again.
To do this on a Mac, select “Open with…”, choose “Other…”, select the Debug player and check the “Always Open With” checkbox.
There is another method document on StackOverflow that I haven’t tried.
Mac OSX / FlashBuilder 4