In LispWorks images shipped on the Windows, Mac OS X, Linux, x86/x64 Solaris and FreeBSD platforms, the IDE starts automatically by default.
If you have an image saved such that the IDE does not start by default, you can start the IDE by calling the function
env:start-environment
. Such an image is shipped for UNIX platforms.
LispWorks User Guide and Reference Manual - 21 Dec 2011