The Windows version of LispWorks 4.2 has a single window MDI interface optionthat is the default (the old multiple window interface can be requested using the Tools > Global Preferences menu.) The MDI option can be seen in Figure 1.3.
Figure 1.3 MDI Interface in Windows version of LispWorks 4.2
Even though the MDI interface is the default, this manual will usually show single windows in figures in order to show more detail for the specific LispWorks tool under discussion.