WabbitEmu integrates with the WabbitCode and provides you an extensible debugger.
Wabbitcode - An integrated development environment with auto-complete, syntax-highlighting, and comprehensive source-level debugging
The fastest Z80 assembler with extra features supporting TI calculator development
Adobe Flash Player Debugger can be very useful for collecting debug information.
Script Debugger provides everything you need to quickly and easily author AppleScripts that work.
Comments