By default, tools windows are re-used where possible. For example, suppose you already have a Listener window (potentially iconified) but do not have an Inspector window. When you choose Window > Tools > Listener , the existing Listener is displayed. When you choose Window > Tools > Inspector , an Inspector is created and displayed.
You can switch off re-use of tool windows. To do this, first raise the Preferences dialog as described in Setting preferences. In the Preferences dialog under Environment > General > Window Options uncheck the Reuse all tools box and click OK . Now, when you choose Window > Tools > Listener a new Listener is created, regardless of whether one already exists, and other tools behave in the same way.
The setting of Reuse all tools will be retained for your subsequent LispWorks sessions.
LispWorks IDE User Guide (Macintosh version) - 25 Nov 2011