Ruffle - An open source Flash player
Microsoft Visual Studio - Microsoft Visual Studio is an integrated development environment (IDE) from Microsoft.
BlueMaxima's Flashpoint - the webgame preservation project.
IntelliJ IDEA - Capable and Ergonomic IDE for JVM
CheerpX for Flash - its adobe flash player in webassembly
Xcode - Xcode is Apple’s powerful integrated development environment for creating great apps for Mac, iPhone, and iPad. Xcode 4 includes the Xcode IDE, instruments, iOS Simulator, and the latest Mac OS X and iOS SDKs.