An Execution Tool lets you execute a system, enter its input, see its output, and save the session's input and outpu. The combination of these tools yields a powerful set of facilities greatly superior to traditional function-based tools. That object is said to be the tool's target. You may for example target a Class Tool to any class of your system, to explore properties of that class and, if necessary, modify it. In any tool you will find some buttons that enable you to perform some actions by clicking.
Some holes also serve as buttons.
Any tool offers you a set of formats enabling you to access various kinds of target information. The System Tool offers formats for editing the system's Ace file, exploring the system's clusters and their classes, obtaining statistics about the system. A Class Tool lets you see the text of the target class, its ancestors, the descendants, clients, suppliers, routines, attributes etc. An Object Tool lets you see the fields of the target object as well as the associated constants. You pick an object in a tool and move it to the appropriate position in the same or another tool.