Script Debugger lets you set an application as your script’s implicit target (the application to which undirected Apple events should be sent). To do so:

• Choose Script > Default Target and select the desired target application.

The application should be running or in the list of known applications (or it can be AppleScript Studio, which appears at the top of the list). When you run your script, the target application must be running. If it isn’t, Script Debugger will offer to launch it.

This feature is useful for simulating runtime environments where there is in fact a significant implicit target. For instance, if you’re going to run a script from BBEdit’s Scripts menu, code targeting BBEdit doesn’t have to appear in a tell block, because you’re “inside” BBEdit already. So you could have a script that uses BBEdit commands and terminology with no tell block. To test or run such a script from within Script Debugger, you need a way to make BBEdit the default target, and that’s what this feature provides.