Flash Builder
Used by 5 peoplehelpx.adobe.com ↗

“For game development, I'm working in Flex Builder, which makes working with Flash actually bearable.”
Jessica Hammer Interview, Game psychologist, designer · via Uses This 
“When I'm doing Flash I use Flash Builder, but that's been less and less frequent as of late.”
Matthew Mckeon Interview, Developer (IBM Visual Communication Lab) · via Uses This