Script Debugger version 1.0 was released in 1995 by Mark Alldritt. It was a third party alternative to Apple's freeware application, Script Editor. Its competitors at that time included ScriptWizard and Main Event Software's popular Scripter. These two products today are defunct, leaving the only other competitors in the field being Satimage's Smile and integrated development environments such as FaceSpan and AppleScript Studio.
Script Debugger contained several notable features: it was "scriptable," (it could be used to create scripts to control itself), recordable, (it could create scripts based on user actions), and attachable, (scripts could be written to respond to events). More importantly, Script Debugger allowed inspection of running applications, to see what events they were emitting. True to its name, Script Debugger also contains a full debugger, with support for breakpoints.
Script Debugger has since won many awards in the Macintosh scripting community. Version 1 received "5 mice" from MacUser and 4 stars from MacWEEK. Version 2 received the 2000 MacWorld Eddy for "Best Development Software", and received "4.5 mice" from both MacUser and MacWorld.