To switch quickly from the Listener to another window, use
Command+~
. To return to the Listener, use
Command+Shift+~
.
These shortcuts cycle through all the windows in turn, and they work in any of the LispWorks IDE windows.
You might also find the tool accelerator keys useful. See Tool accelerator keys.
LispWorks IDE User Guide (Macintosh version) - 25 Nov 2011