LispWorks executables and dynamic libraries have a default startup location which may clash with other software already mapped at that location. Also, a LispWorks image may grow up to an address where other software is already mapped. Where possible LispWorks attempts to avoid such clashes automatically.
If LispWorks fails to use other memory as it grows, the effect will be to limit the size of the Lisp heap, possibly leading to messages
failed to enlarge memory
at the console. On some platforms LispWorks can fail to detect a clash safely, which will lead to unpredictable behavior if it overwrites other code.
The behavior is specific to the particular platform and LispWorks implementation. There is a discussion of these issues (with the platform-specific details) and a description of how you can avoid memory clashes under "Startup relocation" in the LispWorks User Guide and Reference Manual .
LispWorks Delivery User Guide - 13 Dec 2011