Cincom Smalltalk has the most powerful debugger in the world, but even in Smalltalk, there are things that are difficult to debug. For instance, you can’t step through a drag-and-drop operation in the debugger the way you might wish. In this case, you might want something that can watch the message sends without interfering and report them to you; much like the Spy++ tool that Windows API programmers are familiar with. This is exactly the capability we are providing in the next release of Cincom Smalltalk.