Re:Sorry, I find it useless (Score 1)

Actually, Grasshopper add-in includes an integrated debugger (and I know that, as I work in Mainsoft and participated in developing it :0) ). The debugger is transparent - you can debug your application as you debug any other C# / VB application (you may set breakpoints, step through the code, evaluate expressions in the watch window etc.), and you will actually debug the Java application created by the Grasshopper compiler.