3.4 The Break gesture
The keyboard Break gesture is
This chooses a process that is useful to break, and breaks it.
The process to break is chosen as follows:
It checks for a busy processes that is essential for LispWorks to work correctly, or that interacts with the user (normally that means that some CAPI interface uses it), or that is flagged as wanting interrupts (currently that means a REPL). If it finds such a busy process, it breaks it.
Otherwise it activates or starts the Process Browser.
Note: This break gesture is supported only on Mac OS X 10.4 and later.
LispWorks IDE User Guide (Macintosh version) - 12 Feb 2015